13 Bringing it all Together – the New Network Architecture 13.1 INTRODUCTION In Part 2 of the book we have explored some of the key existing services and how they may progress. In this chapter I would like to take you a little way into the future, for a view of what the network may look like and explore how a service or group of services may fit together to form a useful example of where next-generation networks will take us. Let us go over the components of the next-generation network: † Media gateway and signalling gateways, these are the interfaces back to the Time Division Multiplex (TDM) world of the current Public Switched Telephone Network (PSTN) and Public Land Mobile Network (PLMN). † Media gateway controllers (call servers), softswitches and application servers. These are where the new services execute. † Media servers (or Internet Protocol Interactive Voice Response (IP- IVR)), these are the components that provide the voice of the network and automate a number of voice enabled applications. † Directories, these will store all the configuration information about services, users and equipment inventory, for example: † Application-specific configurations for each client/customer. † Personalisation information on a per user basis (buddy lists, prefer- ences, usage statistics, favourites and bookmarks). † Device information and capabilities. Next Generation Network Services Neill Wilkinson Copyright q 2002 John Wiley & Sons, Ltd ISBNs: 0-471-48667-1 (Hardback); 0-470-84603-8 (Electronic) † Location of application components and whole service instances. † Service translations (freephone style service translation info). † Security tokens (access control lists and encryption keys). † User location information. † Virtual Home Environments (VHEs). † Service tags, flags to indicate what the user is allowed to do. For example if someone hasn’t paid their subscription fee, then a flag could be present to prevent them from using any billable services. † User scripts (for example written in Call Processing Language – CPL). † Application scripts (VoiceXML scripts say). † Agent skill sets for call centre applications, the profile of an agent’s capabilities could be held. † Call routing rules. † Billing information and usage records. † The directory will hold the information in Extensible Markup Language (XML), because XML brings with it the power to represent the data in a structured way that allows the display and transforma- tion of that data to and from any device. † Packet network, the infrastructure that supports all the components above. It will be using protocols such as Multi Protocol Label Switch- ing (MPLS) to both segregate traffic flows and to manage quality of service aspects. † Transport infrastructure, this will be fibre optic cables providing high amounts of bandwidth managed via Dense Wave Division Multiplex- ing (DWDM) and broadband copper for low cost Small to Medium Enterprise (SME) and residential access. For mobile devices the access will be via Universal Mobile Telecommunications Service (UMTS) data and voice services. Now that we have the components how do they fit together? They say a picture speaks a thousands words, so I’ll use a picture to give some idea of the architecture. 13.2 THE NEXT-GENERATION NETWORK ARCHITECTURE In the introduction to this chapter we highlighted the components that will make up the next-generation network architecture. Figure 13.1 shows a view of the components and their relationship to each other to form the physical architecture of the network. The technologies such as DWDM and MPLS will form the basic infra- structure (glue) that will interconnect all the nodes. MPLS will be used to segregate the different type of data that will be transported on the infra- BRINGING IT ALL TOGETHER – THE NEW NETWORK ARCHITECTURE168 structure. The data will be one of two types: media streams (voice, video and other forms of content) and control data (signalling). The bottom-most layer will be the media transport layer, in the case of a next-generation network to replace the circuit switched network of tele- coms operator, this layer will carry lots of telephone calls. This is shown in Figure 13.1 as the voice transport layer. Part of this layer’s function will be to groom incoming traffic from the broadband local loop, for example from cable and digital subscriber lines. The media traffic from these custo- mers will be delivered over the media layer and their signalling messages from the intelligent access devices, passed to the signalling layer. Above the media transport layer will be the signalling layer, carrying all the control messages to and from media gateways and their media gate- way controllers, encapsulated Signalling System number 7 (SS#7) signal- ling messages carried from signalling gateways to media gateway controllers and softswitches and session initiation protocol (SIP) messages between SIP clients and proxy, redirect and SIP application servers. The very top layer will be where all the servers reside to allow fast communication between distributed applications and between different service platforms. This layer will also carry all the information to the operational support systems and business support systems for mainte- nance and billing. This layer will also contain all the directories and databases that will store all the location and configuration information about customers/users and the services. This layer could also hold the 13.2 THE NEXT-GENERATION NETWORK ARCHITECTURE Figure 13.1 The next-generation network architecture 169 Service Control Point (SCP) of a conventional circuit switched Intelligent Network (IN). The SCP in this case would have implemented an Internet Protocol (IP) interface and would no doubt be communicating (via stream control transmission protocol) with a media gateway controller or soft- switch masquerading as a service switch point. This would provide old and next-generation network service integration. The final and probably the most important parts of the network will be the firewalls and routers that interconnect the networks of different network operators and service providers. In Figure 13.1 these are shown as firewalls and the interconnect packet filter router. 13.3 A SERVICE EXAMPLE Imagine a couple of young professionals in a few years’ time going about their hectic lives, both have Personal Digital Assistants (PDAs) with voice (UMTS and Digital European Cordless Telephony (DECT)) and video capabilities, plus close proximity Bluetooth capabilities. The service provider they got their PDAs from provided them with basic packages containing a bundle of the following services: location-based advertising from a selection of reputable high street names, real-time stock, traffic and news feeds, access to an online diary/agenda and presence service, with a bundle from their UMTS and fixed line providers that allows them to use their PDAs as fixed line handsets in their homes, because they get free local calls in the evenings from the fixed line provider and of course the now ubiquitous Unified Communications (UC) package. Peter and Jane are both in work, but it’s getting close to the end of the day and Peter feels like he’s had a tough day and would like to eat out and see a movie. He checks Jane’s online diary/agenda to see if she has any late meetings (Jane has previously allowed Peter read access to her diary/ agenda). She doesn’t, so Peter looks up on the web what the local cinema is showing. There is a couple of showings at the 9:30 p.m. slot for the latest summer blockbuster, which he thinks Jane might just be persuaded to watch. So he puts a one hour reservation on two tickets, which he will need to confirm. He’s not sure what food he would like, so he decides to have a stroll into town to have a look around the restaurants to see what takes his eye. On leaving his office building the network detects that he has left his office cell, and this triggers a script that diverts all calls to his office number directly to his UC service. The service script is smart enough (its in the network, so can interrogate the source of contacts) to distinguish work calls from personal calls. Peter has set up an additional list that allows calls he has nominated as personal calls that arrive at his office number, to be routed to his PDA and not the UC platform. Passing the Italian restaurant his PDA flashes up the specials for the BRINGING IT ALL TOGETHER – THE NEW NETWORK ARCHITECTURE170 day, this catches his attention and he really ought to find out if Jane would like Italian and the movie. He goes to his presence service where he has Jane in his buddy list. He sees that Jane is still at work and set to be reached by text messages only. Peter decides Jane must have someone with her who caught her at her desk before she set off for home. Peter sends Jane an instant text message with the film details and the Italian restaurant menu, plus a little note explaining his idea. Jane has got someone with her and simply replies OK to Peter’s message. Peter quickly confirms the tickets for the movie and pays for them with his e- wallet that is linked to his PDA device identity (this creates a record that a transaction took place from Peter’s PDA, the access to the services them- selves are charged, but a small fee is levied from the transaction by Peter’s service provider). Jane finishes her impromptu meeting and quickly looks to her presence service to see if she can tell where Peter is from her buddy list. She can see that Peter is in the middle of town. She quickly calls him as she is leaving the office simply by selecting the icon of Peter in her buddy list. They quickly arrange to meet in a bar where they can decide on dinner. Jane is having second thoughts about the Italian. Having browsed a few more menus together from the bar, they decide on a local Chinese restaurant. After the meal and movie, they leave the cinema to find their train has been cancelled, no driver again, this was sent to both their PDAs as part of the travel updates service they subscribe to, better find a cab. When the couple arrive home, both Jane’s and Peter’s handset swap to DECT for voice and Bluetooth for their home network. Peter and Jane’s PDAs now share a common number and are both just handsets of the same DECT base station. When someone calls the house number, both PDAs will be paged. However, since the PDAs are intelligent devices and can receive caller information over the DECT interface they can apply a local profile that can decide whether to ring (playing a distinctive tune for different callers) or not. Peter and Jane both retire for the evening leaving their PDAs in their cradles. This simple story highlights some of the capabilities of a combined services next-generation network. All of the service features described will be possible in the next 10 years or less, in fact some are appearing at the time of writing! 13.3 A SERVICE EXAMPLE 171