31-03-2010, 12:16 PM
plz send complete information regarding access control mechanism femtocells
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access control mechanism for femtocells
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02-04-2010, 02:01 PM
Access control method for cellular networks comprising femto-cells
On this article, A method of controlling access of a user terminal (UE) to a cell © in a cellular communication network candidate for access by said user terminal (UE) is described. The method includes broadcasting (200) in the cell © at least one signal for reception by said user terminal. The said signal maybe one among the following:
a)a start signal (LU_Start; CellRegistration_Start): Indicates to the user terminal to start immediately a procedure (202) for location update or registration with the cell ©.
b)a reset signal (LAC_Forbidden-Reset; CellForbid-denList_Reset):
It indicates to the user terminal (UE) to remove said Location Area Code broadcast by the cell or said cell ©.
c)a signal that maybe the combination of the signals under a) and b).
Access of a user terminal (UE) to a cell © in a cellular communication network candidate for access by the user terminal (UE) is controlled by broadcasting (200) within the cell © at least one signal (for instance a flag) for reception by the user terminal (UE).
Object and summary:
This aims to further improving the known solutions by avoiding the drawbacks nd achieving the effects sought in the terms of increasing the capability and operating flexibility of a femto system. The invention also relates to a corresponding network, a corresponding user terminal as well as a related computer program product, loadable in the memory of at least one computer and including software code portions for performing the steps of the method of the invention when the product is run on a computer.
for more details on this topic, visit:
http://freepatentsonlineEP2112854.html
http://arxivPS_cache/arxiv/pdf/1002/1002.2964v1.pdf
On this article, A method of controlling access of a user terminal (UE) to a cell © in a cellular communication network candidate for access by said user terminal (UE) is described. The method includes broadcasting (200) in the cell © at least one signal for reception by said user terminal. The said signal maybe one among the following:
a)a start signal (LU_Start; CellRegistration_Start): Indicates to the user terminal to start immediately a procedure (202) for location update or registration with the cell ©.
b)a reset signal (LAC_Forbidden-Reset; CellForbid-denList_Reset):
It indicates to the user terminal (UE) to remove said Location Area Code broadcast by the cell or said cell ©.
c)a signal that maybe the combination of the signals under a) and b).
Access of a user terminal (UE) to a cell © in a cellular communication network candidate for access by the user terminal (UE) is controlled by broadcasting (200) within the cell © at least one signal (for instance a flag) for reception by the user terminal (UE).
Object and summary:
This aims to further improving the known solutions by avoiding the drawbacks nd achieving the effects sought in the terms of increasing the capability and operating flexibility of a femto system. The invention also relates to a corresponding network, a corresponding user terminal as well as a related computer program product, loadable in the memory of at least one computer and including software code portions for performing the steps of the method of the invention when the product is run on a computer.
for more details on this topic, visit:
http://freepatentsonlineEP2112854.html
http://arxivPS_cache/arxiv/pdf/1002/1002.2964v1.pdf
03-03-2012, 05:00 PM
Access control mechanism for femtocells
[attachment=17961]
INTRODUCTION
To remain competitive in the wireless communication market, vendors and operators need to take the reduction of both network cost and complexity as a priority in future deployments of cellular systems. Moreover, the growth of the indoor traffic forces network operators to compete with existing indoor coverage solutions, e.g. WiFi (Wireless Fidelity), DAS (Distributed Antenna System) to maintain their revenues.
Since 2/3 of voice and 90% of data traffic occurs indoors and because macrocells are not very efficient when delivering indoor coverage due to high penetration losses, providing such coverage has become a challenge for the operators. That is why the use of FAPs (Femtocell Access Points) seems a promising approach for coping with this coverage problem. An FAP is a low-cost low-power cellular base station deployed by the end customer. It is expected that femtocells will enhance indoor coverage, but they will also deliver high bandwidths, offer new services, and off-load traffic from existing networks.
HISTORY AND DEVELOPMENT OF FEMTOCELLS
The first interest in femtocells started around 2002 when a group of engineers at Motorola were investigating possible new applications and methodologies that could be used with mobile communications. In addition to developing a mobile television scheme, they also put together a very small UMTS base station.
A couple of years later in 2004, the idea were beginning to gain some momentum and a variety of companies were looking into the idea. In particular two new companies, Ubiquisys and 3WayNetworks were formed in the UK to address the area of femtocells. With the idea gaining momentum, and many more companies investigating femtocell technology, the Femto Forum was set up in July 2007. Its aim was to promote the wide-scale adoption of femtocells. With mounting industry pressure to be able to deploy femto cell technology, the Femto Forum also played a coordinating role in ensuring that the standards were agreed and released as fast as possible.
CHALLENGES AND SOLUTIONS FOR FEMTOCELLS
These benefits are not easy to accomplish. There are still several challenges that vendors and operators must face in order to deploy a large number of FAPs on top of the existing macrocells. Electromagnetic interference remains among the major problems in two-tier networks, being able of hindering the above mentioned benefits and degrading the whole network performance.
In two-tier networks, interference is classified as follows:
• Cross-tier interference is caused by an element of the femtocell tier to the macrocell tier and vice versa.
• Co-tier interference occurs between elements of the same tier, for example, between neighboring femtocells.
The impact of interference depends on the techniques used for allocating the spectral resources to the macrocell and femtocell tiers, as well as on the method used to access the femtocells.
SELECTION OF AN ACCESS CONTROL MECHANISM
Moreover, the selection of an access control mechanism to femtocells has dramatic effects on the performance of the overall network, mainly due to its role on the definition of interference. Different approaches have been proposed:
• Closed access: only a subset of the users, which is defined by the femtocell owner, can connect to the femtocell. This model is referred to as CSG (Closed Subscriber Group).
• Open Access: all customers of the operator have the right to make use of any femtocell.
• Hybrid Access: a limited amount of the femtocell resources are available to all users, while the rest are operated in a CSG manner.
[attachment=17961]
INTRODUCTION
To remain competitive in the wireless communication market, vendors and operators need to take the reduction of both network cost and complexity as a priority in future deployments of cellular systems. Moreover, the growth of the indoor traffic forces network operators to compete with existing indoor coverage solutions, e.g. WiFi (Wireless Fidelity), DAS (Distributed Antenna System) to maintain their revenues.
Since 2/3 of voice and 90% of data traffic occurs indoors and because macrocells are not very efficient when delivering indoor coverage due to high penetration losses, providing such coverage has become a challenge for the operators. That is why the use of FAPs (Femtocell Access Points) seems a promising approach for coping with this coverage problem. An FAP is a low-cost low-power cellular base station deployed by the end customer. It is expected that femtocells will enhance indoor coverage, but they will also deliver high bandwidths, offer new services, and off-load traffic from existing networks.
HISTORY AND DEVELOPMENT OF FEMTOCELLS
The first interest in femtocells started around 2002 when a group of engineers at Motorola were investigating possible new applications and methodologies that could be used with mobile communications. In addition to developing a mobile television scheme, they also put together a very small UMTS base station.
A couple of years later in 2004, the idea were beginning to gain some momentum and a variety of companies were looking into the idea. In particular two new companies, Ubiquisys and 3WayNetworks were formed in the UK to address the area of femtocells. With the idea gaining momentum, and many more companies investigating femtocell technology, the Femto Forum was set up in July 2007. Its aim was to promote the wide-scale adoption of femtocells. With mounting industry pressure to be able to deploy femto cell technology, the Femto Forum also played a coordinating role in ensuring that the standards were agreed and released as fast as possible.
CHALLENGES AND SOLUTIONS FOR FEMTOCELLS
These benefits are not easy to accomplish. There are still several challenges that vendors and operators must face in order to deploy a large number of FAPs on top of the existing macrocells. Electromagnetic interference remains among the major problems in two-tier networks, being able of hindering the above mentioned benefits and degrading the whole network performance.
In two-tier networks, interference is classified as follows:
• Cross-tier interference is caused by an element of the femtocell tier to the macrocell tier and vice versa.
• Co-tier interference occurs between elements of the same tier, for example, between neighboring femtocells.
The impact of interference depends on the techniques used for allocating the spectral resources to the macrocell and femtocell tiers, as well as on the method used to access the femtocells.
SELECTION OF AN ACCESS CONTROL MECHANISM
Moreover, the selection of an access control mechanism to femtocells has dramatic effects on the performance of the overall network, mainly due to its role on the definition of interference. Different approaches have been proposed:
• Closed access: only a subset of the users, which is defined by the femtocell owner, can connect to the femtocell. This model is referred to as CSG (Closed Subscriber Group).
• Open Access: all customers of the operator have the right to make use of any femtocell.
• Hybrid Access: a limited amount of the femtocell resources are available to all users, while the rest are operated in a CSG manner.
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