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Preface
A large class of routing protocols for MANETs, namely, reactive protocols, employs some form of caching to reduce the no. of route discoveries .the simplest form of caching is based on associating a timeout with each cache entry.
Such timer based cache scheme can increase the protocol efficiency. However the timeout is not well tuned, a sever performance degradation arises as entries are removed either too early or too late from the cache .
In this paper, we address the problem designing a proactive protocol scheme that does not rely on any timer-based mechanism. This scheme guarantees that valid cached routes are never removed while stale routes are removed aggressively .This proactive caching scheme has been embedded in the Zone Routing Protocol (ZRP) framework.
1: INTRODUCTION

The term MANET (Mobile Adhoc Network)refers to a multihop packet based wireless network composed of a set of mobile nodes that can communicate and move at the same time , without using any kind of fixed wired infrastructure. MNET are actually self organizing and adaptive networks that can be formed and deformed on-the-fly without the need of any centralized administration.
As for other packet data networks, one “to-one communication in a MANET is achieved by unicast routing each single packet. Routing in MANET is challenging due to the constraints existing on the transmission bandwidth battery power and CPU time and the requirement to cope with the frequent topological changes resulting from the mobility of the nodes. Nodes of a MANET cooperate in the task of routing packets to destination nodes since each node of the network is able to communicate only with those nodes located within its transmission radius R, while the source and destination nodes can be located at a distance much higher than R.
A first attempt to cope with the mobility is to use the specific techniques aimed to tailoring the conventional routing protocols to the mobile environment while preserving their nature. For this reason the protocol designed around such techniques are referred to as table-driven or proactive protocols. To guarantee that routing tables are up to date and reflect the actual network topology, nodes running a protocol continuously exchange route updates and re calculate paths to all possible destinations. The main advantage of the proactive protocols is that a route is immediately available when is needed for data transmissions. However if
The user traffic is not generated, and then resources are wasted due the proactive route update mechanism.
A different approach in the design of the routing protocol is to calculate a path only when it is necessary for data transmission. These types of protocols are called as the reactive protocols or on-demand routing protocols. A reactive protocol is characterized by a path discovery procedure and a maintenance procedure. Path discovery is based on a query “reply cycle that adopts flooding of queries. The destination is eventually reached by the query an at least one reply is generated. Path discovery procedure is called when there is a need for data transmission and the source does not the path to the destination. Discovered paths are maintained by the route maintance procedure until they are no longer in used.
The main advantage of the reactive protocol is that f data traffic is not generated by nodes, and then routing activity is totally absent. The main drawback is the network-wide path discovery required to obtain routing information. Since discovery is based on flooding, such a procedure is very costly. The main strategy to reduce the cost is to defer path discovery as much as possible so that non-optimal but available routes are preferred to the effort of finding the current best path. The natural solution is route caching.
Proactive and reactive approaches are merged in hybrid protocols that aim to combine he advantages of both approaches. The Zone routing protocol (ZRP) is a well example of a hybrid protocol. ZRP is based on the notion of the zone. Each node n is the center of a zone with radius of k hopes, denoted Zk(n).nodes at a distance greater than or equal to k from n belong to Zk(n). A reactive protocol is used by n to reach node outsides its zone .Practically k is set to value much smaller then the network diameter to get a fast convergence of proactive
Component of zone routing protocol. Again caching is useful in ZRP to reduce the path discoveries.
The simplest form of caching is based on timeouts associated with the cach entries. When an entry is cached a timer starts, when the timeout elapses, the entry is removed from the cache. Each time the entry is used, the timer restarts. Therefore the effectiveness of such a scheme depends upon the timeout value associated with a cached route. If the timeout is well tuned the protocol performance is increase; otherwise that will create a problem of removing the cache entry too early or too late from the cache.
So in this seminar report I propose a cache scheme which is based on the notion of a caching-zone whose center is a node called as the cach leader. The leader is responsible for advertising routes, detected during some route discovery, inside its caching zone.
The leader must grantee the correctness of the advertised routes. The leader monitors each advertised route proactively and it sends the control messages inside its caching zone as soon as a route becomes stale. In this report we present an implementation of this ZRP that is ZRP plus a proactive caching scheme and is known as C-ZRP.
2: An overview of the Zone Routing Protocol
ZRP is a hybrid routing protocol which aims to combine the advantages of both the proactive and the reactive approaches. Such a protocol is based on the notion of a routing zone or simply known as a zone. A zone Zk(n)
With radius k is define for each node n as the set of nodes at a distance at most k hopes from n
Zk (n) = {i: H (n, i) <= k},
Where H (I, j) is the distance in number of hops between node i and node j. The node n is called the central node of the routing zone, while a node b such that H (n, b) =k is called a peripheral node of n. while the other nodes are called as the internal nodes.
The protocolâ„¢s architecture is organized into four main components: the inter zone routing protocol (IARP), the interzone routing protocol (IERP), the bordercast protocol(BRP), and a layer-2 neighbor discovery / maintenance protocol (NDP).
For each node n the IAP provides routs proactively to nodes belonging to Zk(n). The value for k is usually small to the network diameter. The IARP can be implemented by any proactive protocol with the limitation that route updates have to be propagated up to a distance of k hops from the central node. IARP uses the NDP service to learn about a nodeâ„¢s neighbors. NDP notifies when a new page link to a neighbor is established or an existing one is deleted.
For those nodes located at a distance k™ > k from the source node, ZRP invokes the IERP component to calculate an interzone path. An inter path from S to D is formed by a sequence of nodes B0 =S, B1, B2, B3, B4¦¦¦¦.Bm, Bm+1 =D, in which node Bi+1is a node within Bi™s routing zone. The path is calculated on demand using a form of selective flooding that exploits the underlying zone structure generated by IARP.
Specifically, flooding is based on sending query packets only to the peripheral nodes (also called border nodes) , using a special kind of multicast transmission dubbed bordercast. When a node receives the query packet for a target node D, it can either reply to the source- if D is a member of its routing zone - or bordercast the query packet to its peripheral nodes. Eventually, the query packet reaches a node having D as a member of its zone so that a reply control packet is generated and send back to the source. A route to D can be accumulated in the query packet during forwarding or - to reduce the query packet length - stored temporarily at nodes and accumulated in the reply control packet during the reply phase.
In ZRP, zones heavily overlap due to the lack of coordination among nodes. As a result, a node can be a member as well as a border node of many zones. Thus, the basic query mechanism can perform even worse than in standard flooding since a node can forward the same query packet many times, while the same zone can be queried more than once.
ZRP provides several solutions to deal with this problem of stopping and controlling redundant query threads, as well as to prevent the sending of redundant queries. Loop back termination (LT) is a mechanism which is able to detect if a query thread returns to a routing zone that it previously queried and to discard the thread accordingly. The Query detection scheme (QD1 and QD2) detect and discard a query thread I it queries a zone already queried by other threads. The QD2 mechanism extends this capability also to nodes that are in the transmission range of the query transmitting node. Early termination extends the capacity t terminate threads also to nodes internal to a zone. Finally selective bordercast prevents thread overlap by using a modified IARP that provides network topology information for an extended zone with a radius of 2k.
A routing pat only contains the border nodes that have to be traversed . Forwarding along border nodes is table driven since the distance between border nodes is k. Route maintenance is responsible for maintaing interzone path.
3: The C-ZRP PRORTOCOL
In this section , we first give an overview of the proactive caching scheme and of the C-ZRP behavior. Then the implementation of the protocol.

1. Overview of the proactive caching scheme
The proposed caching scheme is based on the notion of caching zone, cache leader, and active path.
The caching zone with radius k* for a cache leader n is defined as the set o0f nodes at a distance at most k* hops from n an active path is created as a result of the discover phase and it is composed of a set of nodes, hereafter referred to as active nodes forming a path from source node S to a destination node D. cache leader nodes are a subset of the active nodes.
The key consideration is to avoid the possibility that nodes can cache route information autonomously. Therefore a cache leader n is only the node which is authorized to advertise route information inside its caching zone which is written into caches. On receiving the advertising message, anode proactively maintains a path to n so that it can be used as the next hope node to any of the advertised routes. A cache leader is responsible for the validity of the advertised routes. Thus it monitors such routes and it forces each node in its caching zone to remove a route as soon as it becomes stale. So, the deletion policy is proactive
2. Implementation of the C-ZRP
In the following we provide a description of a possible implementation of C-ZRP. For simplicity the implementation assumes the following aspects as on the next page:
A. All active nodes act as cache leader nodes and vice versa.
B. Only paths to active nodes are advertised as external routes.
C. Caches are managed using explicit injection / deletion message.
D. k = k*.
When a node S executes a route request for a node D, an interzone path from S to D is identified. A node Bi belonging to an interzone path is an active node for caching scheme (an example of interzone path between S and D formed by nodes b, e, p and t is shown in figure.) Thus, an interzone path is an active path. An interzone path is stored according to a distributed next hop fashion, where next-hop node is an active node. Bi stores Bi +1, as the next hop active node for all the downstream nodes from Bi+2 to Bm+1 and Bi-1 is the next hop active node for all the upstream nodes from B0 to Bi-2. These two active nodes will be referred to as companion nodes (as an example the companion nodes of node B with respect to the interzone path from S to D).
All routing information concerning node belonging to an interzone path is advertised inside the caching zone of each member of the path, which thus acts as cache leader for those information. Such routes are then maintained proactively by the IARP. If a new node joins Biâ„¢s zone it acquires by means of IARP, all previously advertised routing information by Bi. Since a node may belong to more than one overlapping zone, it can acquire more than a single path to the same destination.
When a new node, say Bi+1 leaves Bi™s routing zone, not all the routing information gathered during the route request/reply is lost. Roughly, speaking two active paths from S to Bi-1 and from Bi+1 to D are still up. Hence, all the routing information concerning these sub-paths is still valid. However, nodes B0 ¦ Bi-1 (Bi-1 ¦ Bm+1) notify the nodes inside their own zones using a delete control message that the destination the Bi-1 ¦ Bm+1 (B0 ¦ Bi) are no longer reachable.
We remark that both delete and inject messages can be piggy backed on messages regularly exchanged by the proactive routing protocol. However, the use of explicit messages provides a faster reaction to topological changes.
3: Data structures
Each node X uses the following local data structures:
¢ Internal zone routing Table (IZT). An entry of IZT is a triple (d, n, #h), where d is the destination node, n is the next hop node (located in the X™s transmission range) and #h is the path cost in no. of hops.
¢ External zone routing table (EZT): A row of EZT is a triple (d, n, #z), where d is the destination node, n is the next hop active node (n belongs to the X™s transmission range) and #z is the path cost from X to d given as the no. of active nodes that have to be traversed. For example, in Fig.1 node b sets node c as next-hop active node for p with cost two (node c and p).
¢ Interzone path table (IZP): An interzone path corresponds to an entry in X™s IZP table provided that X is an active node and (XS, D). In this case let the path id be ID and X=Bi. The entry is the triple (ID, Bi-1, Bi+1).
¢ Reachable nodes (RN) list. This is a sequence of pairs (d, #z), where d is an active node belonging to an interzone path and #z is the cost of the path from X expressed as number of active nodes that must be transversed to reach d. A node X advertises RN to nodes belonging to Zk(X). RN includes the projection of EZT along the first and third components. For example, node b of Fig.1 will include the pairs (p, 2), (t, 3) and (D, 4) in RN.
¢ Unreachable nodes (UN) set. This set of nodes is used to advertise the destinations that become unreachable.
The following consistency relations are always guaranteed:
(d, n, -) EZT (n,-,-) IZT
(ID,a,b) IZP(a,-,-), (b,-,-) IZT
An example of EZT, IZT and IZP data structures is given in Fig.1
4: IERP and inter zone path management:
When a node S has a new message m t send to a node D, it first checks if either IZT or EZT have an entry for D. if this is in the case , it invokes the IERP for calculating a new path and a new route discovery triggered as in fig 2.
Interzone path creation:
A single inter zone path from S to D is created during a route / request cycle by allowing only the destination D to send a single for a given request. The path is tagged with a unique identifier Id, for example, obtained by using increasing sequence numbers generated by the requesting node. When S triggers a new route discovery for a node D, it bordercast a query message to all its border nodes. The message contains the identifier ID and a route accumulation vector AV [0] =S .let M be the number of active nodes (not including S and D.).
1. When a border node X! =D receives a query message, if the message s received for the first time and the redundant query filter rules are satisfied:
a: it adds its own identification into the accumulation vector as an
Example, if the node X corrospond to node Bj in the interzone path, then AV[j]=X.

b: if D belongs to X's routing zone then the latter unicast the
Query message to D. otherwise , it executes a bordercast.
2. When the destination node D receives a query message with an identifier ID for the first time:
a: It stores the tupple (AV[i],AV[M],M+1-i),for 0<=i<=M.
b: it prepares the list RN=(AV[i], M+1-i)], for 0<=i<=M.
c: it sets AV[M+1] =D.
d: it sends a reply message to AV[M], the message contains the AV vector accumulated in the querry message.
an example of path creation is shown in fig .2C
3. When a border node Bj receives a reply message:

a: if Bj != S then it stores the triple
(ID, AV[ j-1], AV[j+1])
In the IZP table, thus becoming an active node.
b: it stores the following tupple in EZT:
(AV[i], AV[j-1], j-1), for 0<= i <=j-2
(AV[i], AV[j+1], j-1), for j+2<= i <=m+1
c: it prepares RN = [(AV[j+i], ¦i¦)], for “j <= i <= M+1

d: if Bj != S, then it forward the reply message to the node AV[j-1] .
Fig 2b shows the state at node B2 after the reception of the reply message with AV=[S, B1, B2, B3, B4, D] that caused the execution of the following actions:
1: B2 becomes a member of an interzone path (it stores the triple (ID,
B1, B3) in IZP).
2: B2 adds the entries (S, B1, B2), (B4, B3, B2), (D, B3, 3) in the EZT.
3: B2 prepares the list of reachable nodes
RN = [(S, 2), (B1, 1), (B3, 1), (B4, 2), (D, 3)].
4: B2 forwards the reply to B1.
5: Interzone path deletion .

An interzone path is broken at node Bj when Bj-1 ( or Bj+1) is no longer in Bjâ„¢s routing zone. In this case the path is divided in two sub paths and the source node is notified with an error message an active node Bj executes the following actions:
1: delets the entry (-, Bj-1, -)or (-, Bj+1, -) from EZT.
2: checks the companion nodes Bj+1 or Bj-1 in the IZP table.
3: if the companion node is found , then it prepares the following list of
Unreachable nodes: N= [B0, B1, ¦¦, Bj-1] (UN=[Bj+1, Bj+2, ¦..,
Bm+1]) and sends a delete- path message , containing UN and the path
Identifier ID, to the companion node.
4: delets the entry (ID, Bj-1, Bj+1) from the IZP after the successful
Transmission of the message
When an active path is broken, the source node either receives the delete-path message from B1(if the page link is broken between (Bj, Bj+1), with j>0) , or is able to detect the break autonomously via IARP. The source node thus triggers a new route discovery f required to send other packets, while the two subpaths (B0, B1, ¦¦, Bj-1 and Bj+1, Bj+2,¦¦..Bm+1) remains active.
Fig.2c shows the case when the page link between B2 and B3 is broken. Two interzone subpaths, (S, B1, B2), (B3, B4, D)are generated. In the fig B2â„¢s EZT is also shown .
When an active node receives a delete-path message from one of its companion nodes X, it deletes the entries stored in the UN list from the EZT and forwards the message to the other companion node. If the receiving node has some another route to a node stored in UN , then it does not include such a node when forwarding UN.
6: Cache management
so far, we have discussed how a node Bj belonging to an interzone path from S to D acquires route information about all the other nodes of the interzone path. The node stores this information in the EZT data structures and creates the RN list. We now discuss how routes are managed inside the catching zones.
Injecting and maintaining external routes. In order to allow all the nodes of Bjâ„¢s routing zone to use the acquired information , Bj broadcast RN inside its zone. We call such a message the inject message.
On receiving an inject message carrying the reachable node list RN from a node X= Bj, a node Y creates a set of entries ( RN[i].d,X,RN[i].#z)into its own EZT, 0< i < ¦RN¦,where RN[i].d is the first component (destination node) of the ith pair of RN,RN[i].#z, the second component(i.e., the length ),and ¦RN¦ is the number of elements of RN. Fig .3a shows node b2 injecting the external routes to nodes S, B1, B3, B4, D into its zone. Note that y now has two routes to node Bj since such a node is in Y' routing zone.
Deleting external routes.When a node Bj either detects a path breakage or receives a Delete-path message, it broadcasts a delete message into its zone containing the list of unreachable nodes UN.
When an internal node receives a delete message it deletes all the matching entries from EZT. Fig.3b shows the delete mechanism on node Y.
7: IARP
The proactive component of C-ZRP (IARP) relies on a modified Distance Vector algorithm. The Neighbor discovery Protocol (NDP), notifies the IARP when a new page link to a neighbor is established or an exiting one is deleted. When the IARP receives such an event, it sends an update route message to its neighbors. On receiving a route update message, a node calculates the new routing table and sends a new route update to its neighbors. IARP also advertises external routes by sending the triples stored into its own EZT. If the advertised next-hop node of a triple belongs to the routing zone of the receiving node, then such a node adds the entry into its EZT. Note that the next-hop node is not set to the sending node. The IARP uses the value k+1 as infinity. Finally, to guarantee the consistency relations, when a node n leaves X's routing zone, the IARP deletes: the entry (n,-,-) from IZT; all the entries (-,n,-) from EZT; all the entries (-,n,-) and (-,-,n) from IZP.
8: Forwarding a packet
When a node S needs to sent a message m to a destination node D, it checks the IZT table. If an entry (D,n,-) is found, then the message is send to n. Otherwise, S checks the EZT table for an entry (D,n,-). If such an entry exists, then S sends the message to n; otherwise, it triggers a new route discovery. Eventually, a node Y is selected as the next-hop node toward D and the message m is sent to it.
On receiving m, a node Y checks the destination m.dst. If m.dst = Y, then the message is delivered to the upper layer. Otherwise, Y forwards the message according
the following algorithm:
Forward (m,D);
if (D,n,-) ‚¬ IZT then
ucast(m) to n;
else if (D, n*, #Z) ‚¬ EZT then
/* choose the lowest #z if multiple matches*/
Let (n*, n, -) ‚¬ IZT;
Ucast (m) to n;
4: Performance results:
In this section, we present the protocol performance obtained by means of simulations. We observe ZRP for a fixed simulation period o 1,000 sec. Under the same traffic and mobility patterns and compare its behavior against the C-ZRP.
1imulation model: each node moves in a 1,500 * 1,500 meter-square, square region according to a random way point model: the nodes alternates between a pause state and a moving state , i.e., it stays in a place for a fixed time interval, called the pause time (PT), and then it moves to a random destination point in the region at a constant speed V = 5 m / s. PT is given as a percentage of the simulation period and its value establishes the mobility degree.
Node movement and traffic generation are mutually independent. Traffic activity is modeled as Constant Bi Rate (CBR) sources. Only a subset of nodes (the sending subset) can generate the traffic directed to a fixed subset (the destination subset). The sending and destination subset are disjoint and are composed of of he same number of nodes.
For each node of the sending subset generates L = 512-byte packets at a rate message / second over a C = 2 Mbps channel. A packet is destined to a randomly selected node belonging to the destination subset. A unicast or broad cast message is successfully received by the target node, provided it is at a distance at most R = 250 m from the sending node. Data packets are sent on behalf of application are received Ta = 2 ms after its transmission. Similarly, the transmission time of the shorter routing message is Tr = 1 ms.
Parameter Symbol Values
Simulation Time 1000 sec
No. of Nodes N 100
Node Speed V 5 m/s
Pause Time PT 5,10,20,40,70,100 %
Transmission Radius R 250 m
Routing Zone Radius K 1 to 5 hops
Message Transmission Ratio 1,2,4,8,12,16 msg/s
No. Of Active Station A 5,25
Total Offered Load A
Message Length L 512 Bytes
Transmission Capacity C 2.0 Mbps
Application Packet Transmission Time Ta 2 ms
Routing Packet Transmission Time Tr 1 ms
TABLE 1 SIMULATION PARAMETER
2: Routing Table Hit Rate
Fig. shows the percentage of time a sending node S used a route to the destination D from its routing table, either IZT or EZT ( the routing table hit rate), as a function of PT for A=5 or A=25 and =1 messages /second.
As excepted, this value increases with PT . Infact the higher the value of PT, the lower the mobility, and thus the higher the time interval a route remains in the tables. In this way, the probability that the entry will be used to send a message to D increases. For PT =100% , the network is static and , thus, pass are learned ones , either via a route discovery or via an inject message. Since this information is always valid the hit rate approaches 100%.
3: No. of Discoveries
Table 2 list the total no. of route requests observe during a simulation when A=25 and =4 messages/sec. For PT=70% and 20%.

TABLE 2 REDUCTIONS IN DISOVERIES
Protocol Route requests
ZRP PT=70% 2709
C-ZRP PT=70% 330
ZRP PT=20% 6229
C-ZRP PT=20% 2199

Conclusions

Starting from the observation that guaranteeing the validity of cached paths at a node is critical to achieving good performance in reactive routing protocols, in this paper, we proposed a new cache mechanism, based on the notion of caching zone, which proactively removes stale information from the caches of all the nodes in a MANET.
The basic idea is to cache topology information associated with an active path and to use control message to remove stale information as soon as the path is broken. The caching scheme is therefore does not rely on any timeout associated with the cache entry, thus avoiding he burden of timeout estimation. Hence we advised a routing protocol, naming C-ZRP, by combining the zone based caching mechanism with the ZRP routing protocol. Finally we show the result after comparison of the C-ZRP and ZRP. In which we have shown that the number of the path discoveries is to much less than that of in the case of the ZRP.
REFERENCE:
IEEE TRANSACTIONS ON COMPUTERS
Vol. 52, No. 8. August 2003

can anyone share me a report about MANET Routing.it has many protocol.thank you in advance

please read http://studentbank.in/report-a-secure-ro...oc-network for getting Mobile Adhoc Network MANET more information and report

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Mobile Adhoc Network MANET full report
INTRODUCTION

Andreas Tønnesen
andreto[at]olsr.org

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The term MANET (Mobile Adhoc Network)refers to a multihop packet based wireless network composed of a set of mobile nodes that can communicate and move at the same time , without using any kind of fixed wired infrastructure. MNET are actually self organizing and adaptive networks that can be formed and deformed on-the-fly without the need of any centralized administration.
As for other packet data networks, one “to-one communication in a MANET is achieved by unicast routing each single packet. Routing in MANET is challenging due to the constraints existing on the transmission bandwidth battery power and CPU time and the requirement to cope with the frequent topological changes resulting from the mobility of the nodes. Nodes of a MANET cooperate in the task of routing packets to destination nodes since each node of the network is able to communicate only with those nodes located within its transmission radius R, while the source and destination nodes can be located at a distance much higher than R.
A first attempt to cope with the mobility is to use the specific techniques aimed to tailoring the conventional routing protocols to the mobile environment while preserving their nature. For this reason the protocol designed around such techniques are referred to as table-driven or proactive protocols. To guarantee that routing tables are up to date and reflect the actual network topology, nodes running a protocol continuously exchange route updates and re calculate paths to all possible destinations. The main advantage of the proactive protocols is that a route is immediately available when is needed for data transmissions. However if
The user traffic is not generated, and then resources are wasted due the proactive route update mechanism.
A different approach in the design of the routing protocol is to calculate a path only when it is necessary for data transmission. These types of protocols are called as the reactive protocols or on-demand routing protocols. A reactive protocol is characterized by a path discovery procedure and a maintenance procedure. Path discovery is based on a query “reply cycle that adopts flooding of queries. The destination is eventually reached by the query an at least one reply is generated. Path discovery procedure is called when there is a need for data transmission and the source does not the path to the destination. Discovered paths are maintained by the route maintance procedure until they are no longer in used.
The main advantage of the reactive protocol is that f data traffic is not generated by nodes, and then routing activity is totally absent. The main drawback is the network-wide path discovery required to obtain routing information. Since discovery is based on flooding, such a procedure is very costly. The main strategy to reduce the cost is to defer path discovery as much as possible so that non-optimal but available routes are preferred to the effort of finding the current best path. The natural solution is route caching.
Proactive and reactive approaches are merged in hybrid protocols that aim to combine he advantages of both approaches. The Zone routing protocol (ZRP) is a well example of a hybrid protocol. ZRP is based on the notion of the zone. Each node n is the center of a zone with radius of k hopes, denoted Zk(n).nodes at a distance greater than or equal to k from n belong to Zk(n). A reactive protocol is used by n to reach node outsides its zone .Practically k is set to value much smaller then the network diameter to get a fast convergence of proactive
Component of zone routing protocol. Again caching is useful in ZRP to reduce the path discoveries.
The simplest form of caching is based on timeouts associated with the cach entries. When an entry is cached a timer starts, when the timeout elapses, the entry is removed from the cache. Each time the entry is used, the timer restarts. Therefore the effectiveness of such a scheme depends upon the timeout value associated with a cached route. If the timeout is well tuned the protocol performance is increase; otherwise that will create a problem of removing the cache entry too early or too late from the cache.
So in this seminar report I propose a cache scheme which is based on the notion of a caching-zone whose center is a node called as the cach leader. The leader is responsible for advertising routes, detected during some route discovery, inside its caching zone.

Reference: http://studentbank.in/report-mobile-adho...z11fuHxKQL

[attachment=5478]

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This article is presented by:
Omar O. Aldawibi, Bayan S. Sharif and Charalampos C. Tsimenidis
School of Electrical, Electronic and Computer Engineering
Newcastle University, NE1 7RU, UK

Distance Awareness Scheduling for Single-Hop
Underwater Ad-Hoc Network

ABSTRACT
Underwater acoustic networks (UAN) are becoming an integral part of a wide range of applications, such as those used for exploration and maintenance in the offshore oil and gas industry, surveillance for homeland security, subsea mine counter measures, marine environmental assessment and diving activities. For UAN, efficient and effective media access control (MAC) is a very important requirement to address the challenges of dense network deployment and shared communication media. Several types of MAC protocols have been developed for radio networks; however, they are not directly adaptable to UAN due to the significant differences between terrestrial radio and underwater acoustic channels. In this paper, we propose a scheduling protocol according to distance awareness to combat propagation delays for ad hoc UAN. The network module and related assumptions are outlined, and a performance analysis, looking at packet transmission probability, maximum saturation throughput and average end to end delay, is also presented. Analytical and practical scenarios and simulations, including network topology, parameters and results, have been discussed.
INTRODUCTION
Underwater acoustic networks have become a powerful technique for aquatic applications, and have recently attracted a great deal of attention from the networking research community . Efficient and effective media access control (MAC) is very important due to dense network deployment and shared communication media. With it, better performance of underwater acoustic networks can be achieved . Different applications require different types of MAC protocols. Several types of MAC protocols have been developed for radio networks; however, they are not directly adaptable to UAN due to the significant differences between terrestrial radio and underwater acoustic channels. MAC protocols can be generally divided into two categories . contention-free protocols and contentionbased protocols. Contention-free protocols include TDMA, FDMA and CMDA, where communication channels are separated into time, frequency or code domains. FDMA is unsuitable for underwater channels because of limited available bandwidth. Furthermore, synchronization in TDMA and the near-far problem in CDMA are two other issues to consider. Consequently, a feasibility study of these protocols in underwater acoustic networks is not easy . Contention-based protocols include random access methods and collision avoidance .In random access the sender transmits the packet without coordination, so packet collision avoidance is totally probabilistic; while in the collision avoidance protocol, the sender and receiver capture the channel through control packets exchanged between them before the data packet has been transmitted . Protocols such as CSMA with collision avoidance based on RTS/CTS protocols are widely used. The performance of random access methods based on RTS/CTS approaches in underwater acoustic networks is determined by several factors. Some research has shown that RTS/CTS-based protocols outperform random access approaches in underwater acoustic networks in terms of energy efficiency. However, the use of a RTS/CTS-based protocol to eliminate packet collision completely results in large energy consumption due to the long propagation delay in underwater acoustic networks. In order to avoid collision completely, two conditions must be satisfied: 1) the duration of the RTS should be greater than the maximum propagation delay; and 2) the duration of CTS should be two times greater than the maximum propagation delay, plus the hardware transmit-toreceive transmission time. These two conditions are easy to apply in terrestrial radio networks. However, it is too expensive to apply them to ad hoc underwater acoustic networks due to the fact that large propagation delay makes the size of the control packets large

mobile ad hoc networks

ABSTRACT

We propose and analyze a scalable and efficient cluster-based group key management protocol for secure group communications in mobile ad hoc networks. For scalability and dynamic reconfigurability; we take a cluster-based approach by which group members are broken in to cluster-based subgroups and leaders in subgroups securely communicate with each other to agree on a group key in response to membership change and member mobility events. We show that secrecy requirement for group communication is satisfied. Further, there exists an optimal cluster size that minimizes the total network communication cost as a result of efficiently trading inter-regional vs. intra-regional group key management overheads. We give an analytical expression of the cost involved which allows the optimal cluster size to be identified, when given a set of parameter values characterizing a group communicating system in mobile ad hoc networks.
Many mobile wireless applications nowadays are based on secure group communication by which data is encrypted using an encryption key (called a group key). When a member joins a group, the group key is re keyed so that the new member cannot decrypt the previous messages. This is meant by Backward Secrecy. When a member leaves a group, the group key is re keyed so that the leaving member could not decrypt the messages in future. This is meant by Forward Secrecy.In this paper we propose a reliable and secure cluster-based group key management protocol for secure group communication in mobile ad –hoc networks (MANET). We also propose a Contributory Key Agreement protocol (CKA) for key generation instead of a centralized key server. We break a group in to cluster-based subgroups with a leader in each group. Any changes in these groups will be recorded as a membership change event and other event changes. Each group has a group key and each leader in a group has a leader key, there is also cluster key to identify the clusters. Each of these keys contains information about Id’s of a cluster, group or member.
Conceivably, as the number of group members becomes large, group key management can incur significant overheads and cause a potential system performance bottleneck. For scalability and dynamic management, we propose a two level hierarchical key management architecture adopted from the IETF Group Key Management Architecture to efficiently and securely distribute keys. In our protocol, a leader communicates with the members in the same region using a cluster key. All leaders in the group use a leader key, KLR, for communications among leaders. A group key, KG, is derived from the leader key KG =MAC (KLR, c), where KLR is a leader key and c is a counter to be incremented whenever a group membership change event occurs. The group key (KG) is used for Secure data communications among group members. These three keys are re keyed for secure group communications depending on events that occur in the system

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Mobile Adhoc Network MANET full report wirless network

INTRODUCTION TO WIRELESS NETWORKING

Technological innovations of engineers during the 20 th century have brought a deep change in humanbeing lifestyle. Today when we fly over the modern city at night we see the earth full of footprints made by engineers. The glowing lights remind us of the impact made by electrical engineers; the planes we fly in and the moving cars below remind us of the contributions of mechanical engineers; and high-rise buildings and complex roads remind us of what civil engineers have accomplished. From the eyes of an engineers, the glow of light, the movement of cars, and the complexity of civil infrastructure relates to the challenges in implementation, size of the market, and the impact of the technology on human life. There is, however, one industry whose infrastructure is not seen from the plane because it is mostly buried under the ground, but it is the most complex, it owns the largest market size, and it has enabled us to change our lifestyle by entering the information technology age. This industry is the telecommunication networking industry.

Many organization utilize traditional wire based networking technologies to establish connections among computers. These technologies fall into the following three categories :

(1) Local Area Networks (LANs)
(2) Metropolitan Area Networks (MANs)
(3) Wide Area Networks (WANs)

LANs support the sharing of applications and printers, transfer of files and sending e-mail within a room or building. Today the industry standard for LANs is Ethernet technology. MANs, which can cover the size of a college campus or large city, interconnect LANs by using protocols such as FDDI (Fiber Distributed Data Interface) and depend on leased circuits and optical fiber for transmission of the data. WANs on the other hand utilize telephone circuits, leased lines and private circuits to support worldwide networking by using circuit and packet switching protocols.

Traditional networking technologies offer tremendous capabilities from an office, hotel room or home. Activates such as communicating via e-mail with someone located in a faraway town or conveniently accessing product information from the World Wide Web are the result of widespread networking. But limitations to networking through the use of wire based system exist because one cannot utilize these network services unless proper physical connection with a LAN or telephone connection.

Over the last thirty years, researchers and companies have been busy developing protocols and systems that provide wireless connectivity for LANs, MANs and WANs. This work has not been easy and has met much resistance form and to the users. Today, though technologies are available that fit into all categories of networks and satisfy the need for mobility.

i want full seminaar report on mobile adhoc network

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Mobile Adhoc Network MANET full report


ABSTRACT

Project Title:
An Acknowledgment-Based Approach for the Detection of Routing Misbehavior in MANETs

Introduction:

What is MANET?

As the importance of computers in our daily life increases it also sets new demands for connectivity. Wired solutions have been around for a long time but there is increasing demand on working wireless solutions for connecting to the Internet, reading and sending E-mail messages, changing information in a meeting and so on. There are solutions to these needs, one being wireless local area network that is based on IEEE 802.11 standard. However, there is increasing need for connectivity in situations where there is no base station (i.e. backbone connection) available (for example two or more PDAs need to be connected). This is where ad hoc networks step in.

In Latin, ad hoc means "for this," further meaning "for this purpose only.- It is a good and emblematic description of the idea why ad hoc networks are needed. They can be set up anywhere without any need for external infrastructure (like wires or base stations). They are often mobile and that's why a term MANET is often used when talking about Mobile Ad hoc NETworks. MANETs are often defined as follows: A "mobile ad hoc network" (MANET) is an autonomous system of mobile routers (and associated hosts) connected by wireless links - the union of which forms an arbitrary graph. The routers are free to move randomly and organize themselves arbitrarily; thus, the network's wireless topology may change rapidly and unpredictably. Such a network may operate in a standalone fashion, or may be connected to the larger Internet. The strength of the connection can change rapidly in time or even disappear completely. Nodes can appear, disappear and re-appear as the time goes on and all the time the network connections should work between the nodes that are part of it. As one can easily imagine, the situation in ad hoc networks with respect to ensuring connectivity and robustness is much more demanding than in the wired case.
Ad hoc networks are networks are not (necessarily) connected to any static (i.e. wired) infrastructure. An ad-hoc network is a LAN or other small network, especially one with wireless connections, in which some of the network devices are part of the network only for the duration of a communications session or, in the case of mobile or portable devices, while in some close proximity to the rest of the network. The ad hoc network is a communication network without a pre-exist network infrastructure. In cellular networks, there is a network infrastructure represented by the base-stations, Radio network controllers,… etc. In ad hoc networks every communication terminal (or radio terminal RT) communicates with its partner to perform peer to peer communication. If the required RT is not a neighbour to the initiated call RT (outside the coverage area of the RT), then the other intermediate RTs are used to perform the communication link. This is called multi-hope peer to peer communication. This collaboration between the RTs is very important in the ad hoc networks. In ad hoc networks all the communication network protocols should be distributed throughout the communication terminals (i.e. the communication terminals should be independent and highly cooperative).

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Ad Hoc Networks and Routing Protocols


Presented By :
Karthik Samudram Jayaraman

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Introduction

What is Ad Hoc Network?


In Latin, ad hoc means "for this," further meaning "for this purpose only.”
All nodes are mobile and can be connected dynamically in an arbitrary manner.
No default router available.
Potentially every node becomes a router: must be able to forward traffic on behalf of others.

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MANET - mobile adhoc network

GUIDED BY :
Mr M.K.PATEL
(Lect ,CE.Dept)
(L.C.I.T.,BHANDU)

prepared by:
SAMIR PATEL(39)
RUCHIN PATEL(38)

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Types of Wireless Networks

Infrastructure based(Cellular Network).

Infrastructureless Network(Mobile Ad hoc
NETwork) (MANET).


INTRODUCTION


Rapidly deployable, self configuring.
No need for existing infrastructure.
Wireless links.
Nodes are mobile, topology can be very dynamic.
Nodes must be able to relay traffic since
communicating nodes might be out of range.
A MANET can be a standalone network or it can
be connected to external networks(Internet).


History of MANETs

Earliest MANETs were called “packet radio” networks, sponsored by DARPA (1970)
These packet radio systems predated the Internet and were part of motivation of the original IP suite
Later DARPA experiments included the Survivable Radio Network (SURAN) project (1980s)
1990s – the advent of inexpensive 802.11 radio cards for personal computer
Current MANETs are designed primary for military utility; examples include JTRS (Joint Tactical Radio System) and NTDR (Near-Term Digital Radio).

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Introduction
Importance of networking
Computer network – system for communication between computers (fixed, temporary)
History starts with Advanced Research Projects Agency (ARPA) in 1962
1969 the beginning of ARPANet which connected University of LA, SRI, University of California at Santa Barbara, and the University of Utah
Mobile Ad-hoc Network
Self-configuring network of mobile routers (and associated hosts) connected by wireless links
This union forms a random topology
Routers move randomly free
Topology changes rapidly and unpredictably
Standalone fashion or connected to the larger Internet
Suitable for emergency situations like natural or human-induced disasters, military conflicts, emergency medical situations, etc.
Mobile Ad-hoc Network
Ad-hoc network versus Mobile Ad-hoc network
Increase of mobile applications
Additional challenges
Changes to the network topology
Need of extreme network flexibility
Answer = Mobile Ad-hoc Network
While MANETs are self contained, they can also be tied to an IP-based global or local network – Hybrid MANETs
Hybrid Mobile Ad-hoc Network
Hybrid Mobile Ad-hoc Network
Hybrid Mobile Ad-hoc Network
Hybrid Mobile Ad-hoc Network
Hybrid Mobile Ad-hoc Network
History of MANETs
Earliest MANETs were called “packet radio” networks, sponsored by DARPA (1970)
These packet radio systems predated the Internet and were part of motivation of the original IP suite
Later DARPA experiments included the Survivable Radio Network (SURAN) project (1980s)
1990s – the advent of inexpensive 802.11 radio cards for personal computer
Current MANETs are designed primary for military utility; examples include JTRS (Joint Tactical Radio System) and NTDR (Near-Term Digital Radio).
Routing Protocols for MANETs
Two types of routing protocols:
Table-Driven Routing Protocols
Destination-Sequenced Distance-Vector Routing (DSDV)
Clusterhead Gateway Switch Routing (CGSR)
The Wireless Routing Protocol (WRP)
Source-Initiated On-Demand Routing Protocols
Ad-Hoc On-Demand Distance Vector Routing (AODV)
Dynamic Source Routing (DSR)
Temporally-Ordered Routing Algorithm (TORA)
Associativity-Based Routing (ABR)
Signal Stability Routing (SSR)
Routing Protocols for MANETs
Destination-Sequenced Distance-Vector Routing (DSDV)
Table-driven algorithm based on the classical Bellman-Ford routing mechanism
Improvements – freedom of loops in routing tables
Routing is achieved by using routing tables maintained by each node
The main complexity in DSDV is in generating and maintaining these routing tables
Clusterhead Gateway Switch Routing (CGSR)
Uses DSDV as an underlying protocol and Least Cluster Change (LCC) clustering algorithm
A clusterhead is able to control a group of ad-hoc hosts
Each node maintains 2 tables:
A cluster member table, containing the cluster head for each destination node
A DV-routing table, containing the next hop to the destination
The routing principle:
Lookup of the clusterhead of the destination node
Lookup of next hop
Packet send to destination
Destination clusterhead delivers packet

Clusterhead Gateway Switch Routing (CGSR)
Clusterhead Gateway Switch Routing (CGSR)
Drawbacks: too frequent cluster head selection can be an overhead and cluster nodes and Gateway can be a bottleneck
The Wireless Routing Protocol (WRP)
Table-based protocol with the goal of maintaining routing information among all nodes in the network
Each node is responsible for four tables:
Distance table
Routing table
Link-cost table
Message retransmission list (MRL) table
Link exchanges are propagated using update messages sent between neighboring nodes
Hello messages are periodically exchanged between neighbors
This protocol avoids count-to-infinity problem by forcing each node to check predecessor information
Drawbacks: 4 tables requires a large amount of memory and periodic hello message consumes power and bandwidth
Source-Initiated On-Demand Routing Protocols
Ad-Hoc On-Demand Distance Vector Routing (AODV)
Builds on DSDV algorithm and the improvement is on minimising the number of required broadcasts by creating routes on an on-demand basis (not maintaining a complete list of routes)
Broadcast is used for route request
Advantages: uses bandwidth efficiently, is responsive to changes in topology, is scalable and ensures loop free routing
Drawbacks: nodes use the routing caches to reply to route queries. Result: “uncontrolled” replies and repetitive updates in hosts’ caches yet early queries cannot stop the propagation of all query messages which are flooded all over the network

Dynamic Source Routing (DSR)
Based on the concept of source routing
Mobile nodes are required to maintain route caches that contain the source routes of which the mobile is aware
2 major phases:
Route discovery – uses route request and route reply packets
Route maintenance – uses route error packets and acknowledgments
Advantages: No periodic hello message and fast recovery - cache can store multiple paths to a destination
Drawbacks: the packets may be forwarded along stale cached routes. It has a major scalability problem due to the nature of source routing. Same as AODV, nodes use the routing caches to reply to route queries
Temporally-Ordered Routing Algorithm (TORA)
Highly adaptive, loop-free, distributed routing algorithm based on the concept of page link reversal
Proposed to operate in a highly dynamic mobile networking environment
It is source initiated and provides multiple routes for any desired source/ destination pair
This algorithm requires the need for synchronized clocks
Temporally-Ordered Routing Algorithm (TORA)
3 basic functions:
Route creation
Route maintenance
Route erasure
Advantages: provides loop free paths at all instants and multiple routes so that if one path is not available, other is readily available. It establishes routes quickly so that they may be used before the topology changes.
Drawbacks: exhibits instability behavior similar to "count-to-infinity" problem in distance vector routing protocols.
Associativity-Based Routing (ABR)
Free from loops, deadlock, and packet duplicates, and defines a new routing metric for ad-hoc mobile networks
Each node generates periodic beacons (hello messages) to signify its existence to the neighbors
These beacons are used to update the associativity table of each node
With the temporal stability and the associativity table the nodes are able to classify each neighbor page link as stable or unstable
Associativity-Based Routing (ABR)
ABR consists of 3 phases:
Route Discovery
Route Repair/Reconstruction
Route Delete
If node A has in his Route Cache a route to the destination E, this route is immediately used. If not, the Route Discovery protocol is started
Associativity-Based Routing (ABR)
Associativity-Based Routing (ABR)
Advantages: free from duplicate packets
Drawbacks: Short beaconing interval to reflect association degree precisely
Signal Stability Routing (SSR)
descendent of ABR and ABR predates SSR
it selects routes based on signal strength between nodes and on a node’s location stability thus offers little novelty
SSR route selection criteria has effect of choosing routes that have ‘stronger’ connectivity and it can be divided into:
Dynamic Routing Protocol (DRP) or
Static Routing Protocol (SRP)
Signal Stability Routing (SSR)
DRP is responsible for maintenance of signal stability table and routing table
SRP processes packets by passing the packets up the stack if it is the intended receiver and forwarding the packet if it is not
Advantages: to select strong connection leads to fewer route reconstruction
Drawbacks: long delay since intermediate nodes can’t answer the path (unlike AODV, DSR)

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Organization
Introduction to Mobile Ad hoc networks (MANET).
Routing in MANET.
Advantages and Disadvantages.
Future Aspects.
Introduction to Manet

Location for the routers is fixed.
The mobile nodes can only communicate over a one-hop wireless page link to the base-station, multi-hop wireless links are not possible.
Cellular networks consist of a wired backbone which connects the base-stations.
Infrastructure dependent.
High setup costs.
Large setup time.
Reliable.



MANET stands for Mobile Ad-hoc Networking.
Links between the nodes can change during time, new nodes can join the network, and other nodes can leave it.
MANET has no permanent infrastructure at all. All mobile nodes act as mobile routers.
Mobile hosts.
Multi-hop routes between nodes.
Does not use large infrastructure.

Hybrid Networks
In hybrid networks the concepts of cellular networks and mobile ad-hoc networks are mixed.
On one side we have a cellular network, on the other side there are mobile nodes with routing facilities.
The idea is to gain more efficiency out of the existing infrastructure, to cover wider areas with less fixed antennas and base-stations and to reduce power consumption.


Characteristics of MANETs
Dynamic topology
links formed and broken with mobility.



Possibly uni-directional links.
Constrained resources.
battery power.
wireless transmitter range.

thank you...
good work. keep it up...

Presented by:
PUROHIT PRIYANK Y.

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Mobile Ad-hoc Networks (MANET)
A introduction to MANET
 In Latin, ad hoc means "for this," further meaning "for this purpose only.- It is a good and description of the idea why ad hoc networks are needed. They can be set up anywhere without any need for external infrastructure (like wires or base stations). They are often mobile and that's why a term MANET is often used when talking about Mobile Ad hoc NETworks. MANETs are often defined as follows: A "mobile ad hoc network" (MANET) is an autonomous system of mobile routers (and associated hosts) connected by wireless links - the union of which forms an arbitrary graph.
WHAT IS MANET ?
 MANET – (Mobile Ad-Hoc NETwork) a system of mobile nodes (laptops, sensors, etc.) interfacing without the assistance of centralized infrastructure (access points, bridges, etc.)
 Rapidly extend, self configuring.
 No need for existing infrastructure.
 Wireless links.
 Nodes are mobile, topology can be very dynamic.
 A MANET can be a standalone network or it can be connected to external networks (Internet).
 Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Each must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. Such networks may operate by themselves or may be connected to the larger Internet.
 In an ad-hoc wireless network all of the devices are wireless. There is no need for an infrastructure connection. If you want to transfer a file from one laptop to another there is no need for a wired connection.
Ad-hoc connections are temporary, and not designed to stay around for long periods of time. They are connections between mobile devices and do not need to connect to other parts of a network.
Example of a MANET
Types of MANET
 Vehicular Ad Hoc Networks (VANETs) are used for communication among vehicles and between vehicles and roadside equipment.
 Intelligent vehicular ad hoc networks (InVANETs) are a kind of artificial intelligence that helps vehicles to behave in intelligent manners during vehicle-to-vehicle collisions, accidents, drunken driving etc.
 Internet Based Mobile Ad hoc Networks (iMANET) are ad hoc networks that page link mobile nodes and fixed Internet-gateway nodes.
CHARACTERISTICS ?
 Communication via wireless.
 Nodes can perform the roles of both hosts and routers.
 No centralized controller and infrastructure. essential mutual trust.
 Dynamic network topology.
 Autonomous, no infrastructure needed.
 Can be set up anywhere.
 Energy constraints
 Limited security
 five main security services for MANETs:
 Authentication :means that correct identity is known to communicating partner;
 Confidentiality means certain message information is kept secure from unauthorized party;
 Integrity means message is unaltered during the communication;
 No repudiation means the origin of a message cannot deny having sent the message;
 availability means the normal service provision in face of all kinds of attacks
APPLICATION AREAS ?
 Military or police exercises.
 Disaster relief operations.
 Mine site operations.
 Urgent Business meetings
Advantages
• They provide access to information and services regardless of geographic position.
• These networks can be set up at any place and time.
• These networks work without any pre-existing infrastructure.
Disadvantages
• Limited resources. Limited physical security.
• Intrinsic mutual trust vulnerable to attacks.
Lack of authorization facilities.
• Volatile network topology makes it hard to
detect malicious nodes.

Mobile ad hoc network (MANET):
Communication has become very important for people to exchange information anytime from and to anywhere. Mobile Ad hoc Networks, called MANETs, are becoming useful as the existing wireless infrastructure is expensive and inconvenient to use. They are going to become integral part of next generation mobile services. A MANET is a collection of wireless nodes that can dynamically form a network to exchange information without using any pre-existing fixed network infrastructure. The abilities of ad hoc networks are recognized and it is used for security-sensitive operations, although there is a trend to adopt ad hoc networks for commercial uses due to their unique properties.
During the last decade, advances in both hardware and software techniques have resulted in mobile hosts and wireless networking common and miscellaneous. Generally there are two distinct approaches for enabling wireless mobile units to communicate with each other: Infrastructured and Infrastructureless. Traditionally wireless mobile networks are based on the cellular concept and relied on good infrastructure support, in which mobile devices communicate with access points like base stations connected to the fixed network infrastructure. Typical examples of this kind of wireless networks are GSM, UMTS, WLL, WLAN, etc.
Infrastructureless approach is commonly known as a mobile ad hoc network (MANET). A MANET is a collection of wireless nodes that can dynamically form a network to exchange information without using any pre-existing fixed network infrastructure.
MANET v/s WLAN
MANETs are dynamically created and maintained by the individual nodes comprising the network. They do not require a pre-existing architecture for communication purposes and do not rely on any type of wired infrastructure; in an ad hoc network all communication occurs through a wireless median.
MANET comprises a special subset of wireless networks since they do not require the existence of a centralized message-passing device. Simple wireless networks require the existence of access points or static base stations, which are responsible for routing messages to and from mobile nodes within the specified transmission area.
Ad hoc networks, on the other hand, do not require the existence of any device other than two or more MNs willing to cooperatively form a network. Instead of relying on a wired base station to coordinate the flow of messages to each mobile node, the individual mobile nodes form their own network and forward packets to and from each other. This adaptive behaviour allows a network to be quickly formed even under the most adverse conditions.

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Mobile Ad Hoc Networks
Types of Mobile Networks
• Infrastructure networks
• Infrastructureless networks
Infrastructure Networks
 It is based on the cellular concept And It has good infrastructure .
 In infrastructure network the mobile devices are communicate with the others through base stations connected to the fixed network infrastructure.
Infrastructureless Networks
 In infrastructureless network the mobile wireless network is commonly known as mobile adhoc network (MANET).
 A MANET is a collection of wireless nodes that can dynamically form a network to exchange information without using any pre-existing network infrastructure.
Characteristics of MANET
• Infrastructure-less or with minimum infrastructure support.
• Self-organizing and self-managing.
• Most or all of the nodes are mobile.
• Network topology changes dynamically.
• Wireless communication.
• Node is working as a host and a router.
• Multi-hop.
Applications of MANET
• Military battlefield.
• Commercial sector.
• Local level.
• Personal area network.
• Etc
• Military battlefield
-- adhoc networking would allow the
military to take advantage of common place network technology to maintain an information between the soldiers, vehicles and military information head quarters.
• Commercial sector
-- adhoc networking can be used in emergency or any commercial area (business).
Ex:hip- to- ship adhoc mobile communication.
Personal area network (PAN)
-- adhoc network can be used to
transfer the short –message between
various mobile devices.
Ex:: wireless LAN.
• Benefits from MANET
• Communication cost becomes cheaper.
• Self Network extended.
• Low Cost for building a network.
• Resources sharing.
• Route Discovery in MANET
• Route Reply in MANET
• Data Delivery in MANET
• Route Error (RERR)
• MANET Challenges
• Research Issues
• x-cast routing algorithms.
• QOS supporting model.
• Security , Reliability , availability schemes.
• Internetworking mechanisms.
Conclusion
• Ad Hoc Networks must connect to the Internet
• Group of Mobile Nodes moving together - Network in Motion

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The manet problem
Mobile
Random and perhaps constantly changing
Ad-hoc
Not engineered
Networks
Elastic data applications which use networks to communicate
WHAT IS MANNET ?
Mobile Adhoc Network (MANET) is a collection of independent mobile nodes that can communicate to each other via radio waves. The mobile nodes that are in radio range of each other can directly communicate, whereas others needs the aid of intermediate nodes to route their packets. These networks are fully distributed ,and can work at any place without the help of any infrastructure. This property makes these networks highly roboust.
Its characteristics
Nodes can perform the roles of both hosts and routers.
Nodes in mobile ad-hoc network are free to move and organize themselves in an arbitrary fashion
No centralized controller and infrastructure.
Intrinsic mutual trust.
Dynamic network topology.
Frequent routing updates.
WHY IT EMERged
Limitations of the Wireless Network
packet loss due to transmission errors
variable capacity links
frequent disconnections/partitions
limited communication bandwidth
Broadcast nature of the communications
Limitations Imposed by Mobility
dynamically changing topologies/routes
lack of mobility awareness by system/applications
Limitations of the Mobile Computer
short battery lifetime
limited capacities
Types of mannet
Vehicular Ad Hoc Networks (VANETs) are used for communication among vehicles and between vehicles and roadside equipment.
Intelligent vehicular ad hoc networks (InVANETs) are a kind of artificial intelligence that helps vehicles to behave in intelligent manners during vehicle-to-vehicle collisions, accidents, drunken driving etc.
Internet Based Mobile Ad hoc Networks (iMANET) are ad hoc networks that page link mobile nodes and fixed Internet-gateway nodes. In such type of networks normal ad hoc routing algorithms don't apply directly.
A Typical MANET
Examples of such networks
Sensor networks
Automotive networks
Military applications
Sensor networks
Networks deployed in random distribution
Low power
Delivering sensor data to a central site for some purpose
Traffic networks
“Smart cars” and “smart roads”
Onboard systems “talk” to the “road”:
Map obstacles and delays
Obtain maps
Inform the road of its actions
Military applications
Combat regiment in the field
Perhaps 4000-8000 objects in constant unpredictable motion…
Intercommunication of forces
Proximity, function, plan of battle
Special issues
Low probability of detection
Random association and topology
OTHER Applications
Personal area networking
cell phone, laptop, ear phone, wrist watch
Military environments
soldiers, tanks, planes
Civilian environments
taxi cab network
meeting rooms
sports stadiums
boats, small aircraft
Emergency operations
search-and-rescue
policing and fire fighting
Medium Access Control in MANET
Exposed Terminal Problem
Hidden Terminal Problem
Exposed terminal problem
In wireless networks, the exposed node problem occurs when a node is prevented from sending packets to other nodes due to a neighboring transmitter. Consider an example of 4 nodes labeled R1, S1, S2, and R2, where the two receivers are out of range of each other, yet the two transmitters in the middle are in range of each other. Here, if a transmission between S1 and R1 is taking place, node S2 is prevented from transmitting to R2 as it concludes after carrier sense that it will interfere with the transmission by its neighbor S1. However note that R2 could still receive the transmission of S2 without interference because it is out of range of S1.

PRESENTED BY:
P. Mahesh Naik

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Wireless Networks
 Need: Access computing and communication services, on the move
 Infrastructure-based Networks
– traditional cellular systems (base station infrastructure)
 Wireless LANs
– Infrared (IrDA) or radio links (Wavelan)
– very flexible within the reception area; ad-hoc networks possible
– low bandwidth compared to wired networks (1-10 Mbit/s)
 Ad hoc Networks
– useful when infrastructure not available, impractical, or expensive
– military applications, rescue, home networking
Cellular Wireless
 Single hop wireless connectivity to the wired world
– Space divided into cells
– A base station is responsible to communicate with hosts in its cell
– Mobile hosts can change cells while communicating
– Hand-off occurs when a mobile host starts communicating via a new base station
Multi-Hop Wireless
 May need to traverse multiple links to reach destination
 Mobility causes route changes
Mobile Ad Hoc Networks (MANET)
 Host movement frequent
 Topology change frequent
 No cellular infrastructure. Multi-hop wireless links.
 Data must be routed via intermediate nodes.
Why Ad Hoc Networks ?
 Setting up of fixed access points and backbone infrastructure is not always viable
– Infrastructure may not be present in a disaster area or war zone
– Infrastructure may not be practical for short-range radios; Bluetooth (range ~ 10m)
 Ad hoc networks:
– Do not need backbone infrastructure support
– Are easy to deploy
– Useful when infrastructure is absent, destroyed or impractical
Many Applications
 Personal area networking
– cell phone, laptop, ear phone, wrist watch
 Military environments
– soldiers, tanks, planes
 Civilian environments
– taxi cab network
– meeting rooms
– sports stadiums
– boats, small aircraft
 Emergency operations
– search-and-rescue
– policing and fire fighting
Challenges in Mobile Environments
• Limitations of the Wireless Network
• packet loss due to transmission errors
• variable capacity links
• frequent disconnections/partitions
• limited communication bandwidth
• Broadcast nature of the communications
• Limitations Imposed by Mobility
• dynamically changing topologies/routes
• lack of mobility awareness by system/applications
• Limitations of the Mobile Computer
• short battery lifetime
• limited capacities
Effect of mobility on the protocol stack
 Application
– new applications and adaptations
 Transport
– congestion and flow control
 Network
– addressing and routing
 Link
– media access and handoff
 Physical
– transmission errors and interference
Medium Access Control in MANET Motivation
 Can we apply media access methods from fixed networks?
 Example CSMA/CD
– Carrier Sense Multiple Access with Collision Detection
– send as soon as the medium is free, listen into the medium if a collision occurs (original method in IEEE 802.3)
 Medium access problems in wireless networks
– signal strength decreases proportional to the square of the distance
– sender would apply CS and CD, but the collisions happen at the receiver
– sender may not “hear” the collision, i.e., CD does not work
– CS might not work, e.g. if a terminal is “hidden”
Hidden and Exposed Terminals
 Hidden terminals
– A sends to B, C cannot receive A
– C wants to send to B, C senses a “free” medium (CS fails)
– collision at B, A cannot receive the collision (CD fails)
– A is “hidden” for C
 Exposed terminals
– B sends to A, C wants to send to another terminal (not A or B)
– C senses carrier, finds medium in use and has to wait
– A is outside the radio range of C, therefore waiting is not necessary
– C is “exposed” to B

PRESENTED BY:
RAKESH K.R

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[attachment=12945]
INTRODUCTION
A "mobile ad hoc network" (MANET) is an autonomous system of mobile routers connected by wireless links.
Rapidly deployable, self configuring.
No need for existing infrastructure.
Wireless links.
Nodes are mobile, topology can be very dynamic.
A MANET can be a standalone network or it can be connected to external networks(Internet).
History of MANETs
FIRST GENERATION:- The first generation goes back to 1972. At the time, they were called PRNET (Packet Radio Networks).
SECOND GENERATION:- The second generation of ad-hoc networks emerged in 1980s,when the ad-hoc network systems were further enhanced and implemented as a part of the SURAN (Survivable Adaptive Radio Networks) program.
THIRD GENERATION:-
Present ad-hoc networks systems are considered as the third generation.
WIRED VS WIRELESS NETWORKS
Wired Networks:- These networks are generally connected with the help of wires and cables.
Wireless Networks:- Wireless networks use some sort of radio frequencies in air to transmit and receive data instead of using some physical cables.
FEATURES OF MANET
Dynamic Topologies.
Bandwidth-constrained, variable capacity links.
Power-constrained operations.
Limited physical security.
ROUTING PROTOCOLS FOR MANET
TABLE DRIVEN PROTOCOL
Table driven protocols are close to wired routing protocols in the manner that the routing table is built before the data has to be sent.
The disadvantage of this principle is to not be reactive to topology changes, as the tables are pre- established.
DESTINATION SEQUENCED DISTANCE VECTOR(DSDV)
ALGORITHM
With DSDV , routing table will contain
The destination address
The number of hops required to reach the destination
The new sequence number, originally stamped by the destination

On-demand style: create routes only when it is desired by the source node
When a node requires a route to a destination,
it initiates a route discovery process
Route is maintained until destination becomes unreachable, or source no longer is interested
in destination.
Ad-Hoc On-Demand Distance Vector Routing (AODV)
Builds on DSDV algorithm and the improvement is on minimising the number of required broadcasts by creating routes on an on-demand basis (not maintaining a complete list of routes)
Broadcast is used for route request
Advantages: uses bandwidth efficiently, is responsive to changes in topology, is scalable and ensures loop free routing
Drawbacks: nodes use the routing caches to reply to route queries. Result: “uncontrolled” replies and repetitive updates in hosts’ caches yet early queries cannot stop the propagation of all query messages which are flooded all over the network
APPLICATIONS OF MANET
Tactical networks
Emergency services
Home and enterprise
Networking
Education
Entertainment
USES OF MOBILE AD HOC NETWORKS 
Extending Coverage
Communicating Where No Infrastructure Exists
Community Networks
PROBLEMS IN MANET
Security
Bandwidth
Energy
Asymmetric Connections
Interference
Dynamic Topology
Routing Overhead
ADVANTAGES AND DISADVANTAGES
The following are the advantages of MANETs:
They provide access to information and services regardless of geographic position.
These networks can be set up at any place and time.
These networks work without any pre-existing infrastructure.
Some of the disadvantages of MANETs are:
Limited resources. Limited physical security.
Intrinsic mutual trust vulnerable to attacks. Lack of authorization facilities.
Volatile network topology makes it hard to detect malicious nodes.
CONCLUSION
The rapid evolution in the field of mobile computing is driving a new alternative way for mobile communication, in which mobile devices form a self-creating, self organising and self-administering wireless network,called a mobile ad hoc network.
As a consequence, the seamless integration of mobile ad hoc networks with other wireless networks and fixed infrastructures will be an essential part of the evolution towards future fourth generation communication networks.

Presented by
Sk.Abdulghani
K.Sandeep reddy

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[attachment=13447]
What is MANET ?
Mobile adhock network
Basaed on the ant-based routing
All nodes communicate via wireless
Problems with Manet
 Network topology changes randomly
 with out a fixed infastructue
 Routing difficult due to mobility of nodes
What is AntHocNet ?
AntHocNet is a new algorithm for MANET routing based on ideas from Ant Colony Optimization (ACO).
Ant Colony Optimization
 Multiple paths
 Ant-like Agents
 Pheromone trail
 Update Tables
AntHocNet
 Hybrid Multipath Algorithm
 Consists of both Reactive and Proactive components
 Less end-to-end delay
 Better packet delivery ratio

PRESENTED BY:
Y.ABHILASH

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[attachment=13534]
MOBILE AD HOC NETWORKS
VRCE
MANET means
. MOBILE
RANDOM AND PERHAPS CONSTANTLY CHANGING
. AD-HOC
NOT ENGINEERED
.NETWORKS
ELASTIC DATA APPLICATIONS WHICH USE NETWORKS TO COMMUNICATE
BASIC IDEA
. A MOBILE AD-HOC NETWORK IS A COLLECTION OF MOBILE DEVICES EQUIPPED WITH A TRANSMITTER AND RECEIVER CONNECT IN THE ABSENCE OF FIXED
INFRASTRUCTURE.
. IT IS A SELF CONFIGURING NETWORK OF MOBILE ROUTERS CONNECTED BY WIRELESS LINKS . HENCE IT IS A ARBITRARY TOPOLOGY.
. THIS NETWORK MAY OPERATE IN STAND ALONE FASHION OR MAY BE CONNECTED
TO LARGE INTERNET.
THE IMPORTANT ROLE THAT A MANET PLAYSIN FUTURE NETWORKS (4G)
LOW COST AND HIGHER EFFICIENCY
1. AS IT HAS NO FIXED INFRASTRUCTURE HENCE WE DON’T HAVE BUILD OUT
COST AND MAINTENANCE COST.
2. WE CAN ACESS HIGH SPEED APPLICATIONS EVEN WHEN THERE IS NO FIXED
INFRASTRUCTURE
PROVIDING NETWORK TO RURAL AREAS
MANET IS GAINING MOMENTUM BECAUSE THEY HELP REALIZING NETWORKS
NETWORK SERVICES FOR MOBILE USER IN AREA WITH NO PRE –EXISTING
INFRASTUCTURE.
. SPONTANEOUS NETWORKING
WHEN A GROUP OF PEOPLE COME TOGETHER FOR A COMPUTER BASED COLLABORATIVE WORK
CHARACTERISTICS
AUTONOMOUS AND INFRASTRUCTURE-LESS
MULTI HOP ROUTING
DYNAMICALLY CHANGING TOPOLOGIES
. VARIATION LINK AND NETWORK CAPABILITIES
APPLICATIONS
MILITARY APPLICATIONS
DISASTER RECOVERY ENVIROMMENTS
TRAFFIC NETWORKS
CHALLENGES FOR MANET
ENERGY CONSTRAINED OPERATION
FAULT DETECTION IS DIFFICULT
PACKET LOSS
HETEROGINITY
SECURITY
ROUTING
ROUTING
TABLE DRIVEN ROUTING PROTOCOL
ON DEMAND ROUTING PROTOCOL
HYBRID ROUTING PROTOCOL
Table Driven Routing Protocol
Proactive.
Each node maintains one or more tables
containing routing information to every other
node in the network.
Tables need to be consistent and up-to-date
view of the network.
Updates propagate through the network
On demand routing protocol
Reactive.
on-demand style: create routes only when it is desired by the source node
When a node requires a route to a destination,
it initiates a route discovery process
Route is maintained until destination becomes unreachable, or source no longer is interested
in destination.
Zone Routing Protocol
Hybrid of table-driven and on-demand!!
From each node, there is a concept of “zone”.
Within each zone, the routing is performed in a
table-driven manner (proactive).
However, a node does not try to keep global
routing information.
For inter-zone routing, on-demand routing is used.

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MOBILE ADHOC NETWORKS (MANETS)



  MOBILE ADOHNETWORKS.pdf (Size: 1.47 MB / Downloads: 9)

INTRODUCTION :

In a mesh network, each node acts as a
router/repeater for other nodes in the network.
These nodes can be fixed pieces of network
infrastructure and/or can be the mobile devices
themselves . Mobile ad hoc networks can be
defined as mobile platforms or nodes that can
move freely and establish ephemera wireless
networks without central entities to control it.
At a first glance, mobile ad hoc networks may
not seem directly related to mobile identity
management. However, identity management
does not necessarily imply a client-server
structure where a user is communicating with a
server. Also peer-to-peer scenarios in which
users communicate directly with other users
are of interest in the context of mobile identity
management. Mobile ad hoc networks
constitute a technical infrastructure that could
provide a base for both traditional client-server
applications as well as peer-to-peer
applications.

II.WORKING OF MOBILE AD-HOC NETWORKS :

The MANET system consists of 3 parts,
namely Wireless Decision Layer (WDL),
Global Network Statistics (GNS) and
pluggable routing controller .

The WDL resides in the kernel
space and handles routing decisions and packet
forwarding. It also maintains a real-time count
of the number of packets it has sent and
received, and exports these counts to the
GNSM through well-defined proc file system
interfaces.


INTEGRATION OF
FUNCTIONALITY IN MANETS :

A. Discovery of a gateway : to an operator
network to obtain a unique IP address and
efficient routing mechanisms to support the
mobility of users inside the ad-hoc network
with minimal overhead.


ROUTING MECHANISMS IN MANET NETWORKING:

The two different routing approaches for
MANET s : hop-by-hop myopic routing and
end-to-end source routing.

A. Myopic Routing:

Each node only determines the next hop a
packet should take toward its final destination.
A node must determine which nodes are within
transmission range, and then determine the
"best" neighbor who can forward the packet
toward the destination.


BETTER APPROACH TO MOBILEADHOC NETWORKS (BATMAN):

B.A.T.M.A.N. (Better Approach to Mobile
Ad-Hoc Networking) is a new routing protocol
for multi-hop ad-hoc mesh networks.
B.A.T.M.A.N uses a simple and robust
algorithm for establishing multi-hop routes in
mobile ad-hoc networks.

A.PROTOCOL ALGORITHM:

The protocol algorithm of B.A.T.M.A.N can
be described as follows: Each node transmits
broadcast messages (originator messages or
OGMs) to inform the neighboring nodes about
it’s existence. These neighbors re-broadcast
the OGMs according to specific rules to inform
their neighbors about the existence of the
original initiator of this message and so on and
so forth. Thus the network is flooded with
originator messages.