07-04-2011, 02:36 PM
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INTRODUCTION
Communication methods are essential to enable the continual expansion of the technological society in which we live. They enable people to exchange ideas, opinions and synchronise all interactions between themselves and others. Telephony is still the predominant method of communication although new techniques, such as electronic mail and mobile communications are becoming more and more popular. Network users are requesting increasingly complex services which cannot be effectively supported by existing network architectures. Also, there is a desire to share data, distribute application processing among network elements and increasing demand for more sophisticated telecommunications services. All of these factors have led to the evolution of new networking architectures.
A particular architecture which has evolved is the Intelligent Network (IN), in which services are provided independently of the bearer networks or equipment vendors. The IN is essentially an architecture which separates the service logic from the telephone exchanges, enabling the establishment of an open platform for uniform service creation, implementation and management. It enables advanced customer orientated services to be rapidly and cost effectively introduced.
THE EXISTING TELECOMMUNICATIONS SYSTEM
In the traditional Plain Old Telephone Service (POTS), the switching systems (known as 'switches') perform the basic call processing. Each supplementary service is a non-reusable software entity that modifies this basic process in the switches. The switching network typically consists of a hierarchy of switches, e.g. a local exchange level, an intermediate exchange
level and a transit exchange level, as shown in figure 1.
In these systems, if the switch based services are situated at the transient (top) level, there is a large overhead for their use. This is because of the number of switches and related trunks that need to be accessed in order to use a service. For this reason, services have been 'migrating' to lower levels of the hierarchy, reducing the overhead for service use. In the extreme case, each local exchange level switch contains the service data, meaning that every service must be loaded into every switch's software before it can be used (see figure 2).
Figure 2 - Provision of services in the POTS environment
Having the services located in the switches complicates service maintenance and addition, especially as the number of services contained in each switch increases. Consequently, the addition of new services occurs very rarely.
There are also a number of economic implications to a network structured in this way.
• A single company is traditionally responsible for running an exchange and all of the services it offers. This means that there is not a competitive market for service provision since the company running the exchange is the only service provider.
• Lack of competition leads to lack of innovation, and so service provision does not progress and the standards of services are not forcedto improve as they would be in a competitive market.
• As previously mentioned, service addition is complicated so it is not feasible for customers to request specific services to suit their business needs. Services are rarely introduced and so when they are, they need to benefit as many network users as possible.
There are various problems with the traditional system other than thoseidentified here. Collectively, they have highlighted the need for a new telecommunications architectures, and in response to this, the Intelligent Network has evolved.
INTELLIGENT NETWORK BASICS
Having identified the inadequacies with the traditional system, it was possible to outline the various changes which needed to be made:
1. Increase Service Velocity: enable the rapid introduction of new services with direct responsiveness to customer needs.
2. Broaden The Range of Services: go beyond traditional voice and databearer services to include information services, broadband and multimedia.
3. Enable a Multivendor Competitive Environment: ensure services will work correctly and consistently on any vendor's equipment.
4. Evolve from Existing Networks: must interwork with and evolve from existing networks since completely replacing existing networks would be far to disruptive and time consuming..
The first step in realising these changes was to remove the service data from the switching network, and locate it in a centralised database, which is accessible to all the switching nodes. The next step was to separate the service logic from the switch and put it into an independent node, called an 'intelligent node'. A single new service can be added to this node, which then
becomes available throughout the whole network.
A real time connection is needed between the network nodes, known as'service switching points' (SSPs), and the intelligent node, known as the'service control points' (SCPs). This fast and standardised interconnection forms the basis of the IN architecture. Figure 3 shows the relationship between these network elements.
INTRODUCTION
Communication methods are essential to enable the continual expansion of the technological society in which we live. They enable people to exchange ideas, opinions and synchronise all interactions between themselves and others. Telephony is still the predominant method of communication although new techniques, such as electronic mail and mobile communications are becoming more and more popular. Network users are requesting increasingly complex services which cannot be effectively supported by existing network architectures. Also, there is a desire to share data, distribute application processing among network elements and increasing demand for more sophisticated telecommunications services. All of these factors have led to the evolution of new networking architectures.
A particular architecture which has evolved is the Intelligent Network (IN), in which services are provided independently of the bearer networks or equipment vendors. The IN is essentially an architecture which separates the service logic from the telephone exchanges, enabling the establishment of an open platform for uniform service creation, implementation and management. It enables advanced customer orientated services to be rapidly and cost effectively introduced.
THE EXISTING TELECOMMUNICATIONS SYSTEM
In the traditional Plain Old Telephone Service (POTS), the switching systems (known as 'switches') perform the basic call processing. Each supplementary service is a non-reusable software entity that modifies this basic process in the switches. The switching network typically consists of a hierarchy of switches, e.g. a local exchange level, an intermediate exchange
level and a transit exchange level, as shown in figure 1.
In these systems, if the switch based services are situated at the transient (top) level, there is a large overhead for their use. This is because of the number of switches and related trunks that need to be accessed in order to use a service. For this reason, services have been 'migrating' to lower levels of the hierarchy, reducing the overhead for service use. In the extreme case, each local exchange level switch contains the service data, meaning that every service must be loaded into every switch's software before it can be used (see figure 2).
Figure 2 - Provision of services in the POTS environment
Having the services located in the switches complicates service maintenance and addition, especially as the number of services contained in each switch increases. Consequently, the addition of new services occurs very rarely.
There are also a number of economic implications to a network structured in this way.
• A single company is traditionally responsible for running an exchange and all of the services it offers. This means that there is not a competitive market for service provision since the company running the exchange is the only service provider.
• Lack of competition leads to lack of innovation, and so service provision does not progress and the standards of services are not forcedto improve as they would be in a competitive market.
• As previously mentioned, service addition is complicated so it is not feasible for customers to request specific services to suit their business needs. Services are rarely introduced and so when they are, they need to benefit as many network users as possible.
There are various problems with the traditional system other than thoseidentified here. Collectively, they have highlighted the need for a new telecommunications architectures, and in response to this, the Intelligent Network has evolved.
INTELLIGENT NETWORK BASICS
Having identified the inadequacies with the traditional system, it was possible to outline the various changes which needed to be made:
1. Increase Service Velocity: enable the rapid introduction of new services with direct responsiveness to customer needs.
2. Broaden The Range of Services: go beyond traditional voice and databearer services to include information services, broadband and multimedia.
3. Enable a Multivendor Competitive Environment: ensure services will work correctly and consistently on any vendor's equipment.
4. Evolve from Existing Networks: must interwork with and evolve from existing networks since completely replacing existing networks would be far to disruptive and time consuming..
The first step in realising these changes was to remove the service data from the switching network, and locate it in a centralised database, which is accessible to all the switching nodes. The next step was to separate the service logic from the switch and put it into an independent node, called an 'intelligent node'. A single new service can be added to this node, which then
becomes available throughout the whole network.
A real time connection is needed between the network nodes, known as'service switching points' (SSPs), and the intelligent node, known as the'service control points' (SCPs). This fast and standardised interconnection forms the basis of the IN architecture. Figure 3 shows the relationship between these network elements.
