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The convergence of fixed and mobile networks

The convergence of fixed and mobile networks is expected to be a boon to all of the players involved, from the equipment vendors and service providers to end-users. The benefits are clear to all involved.  For service providers, lower OPEX, and TCO, and the promise of new revenue-generating applications and for the user, the benefits start with a higher quality of experience by having access to a variety of rich multimedia applications regardless of the device, with a consolidated bill, address book, voice or data mail. This “convergence” has already happened, to some degree, but its definition means different things to different players. For the end-user, who does not care what the underlying infrastructure is, convergence of access to applications is important. She wants to access her company’s directory anywhere in the world regardless of the access device used, for example. For the service provider, the convergence becomes more complex, as it has to consider the following points of convergence, i.e., what should be centralized and what should be distributed:

1. Applications
2. Service Convergence
3. User Session setup
4. Transport network
5. Physical network

For the equipment manufacturers, the decisions lie in how to divide the necessary features across different platforms. To provide the level of convergence that is required by the market, both service providers and equipment vendors need to consider strategic alliances. We have already seen this by consolidations in both industries: for example, wireline service providers buying wireless ones, and equipment vendors providing service and application layers merging with vendors of transport layer.

[Specifically, the case of Service Convergence refers to a provider which has both wireless and wireline networks and is offering bundled triple play plus wireless services. This does not necessarily mean that the service provider has converged its underlying transport or physical layers, or applications.]
 
For the transport layer, IP/MPLS has essentially become the de facto protocol for convergence of all network services. In the mobile infrastructure market, the use of IP is a mandate (‘R99 to R4 to R5 for 3G network deployment) for evolution of the backbone network. For wireline networks, this is not a mandate but most operators have come to understand the undeniable benefits, perhaps primarily from market pressures, of moving to an IP-based backbone. And there in lies the first intersection of wireless and wireline networks. This backbone, however, is of utmost importance in any convergence strategy since it is the focal point for providing the user’s quality of experience.

The underlying reasons for this convergence, however, has come from market forces, mainly the end-users, be it individuals or businesses. The lure of accessing information anytime, anywhere and with any device is the major force behind the convergence of these two worlds. Currently, mobile phones, PDAs, or terminals, are used by close a 2 billion users. These devices have resources that have transformed the meaning of “applications”. Some applications are natural extensions of the current wireline ones, e.g., mobile IPTV, as the service in Korea. Increasingly, applications now are more focused on Peer-to-Peer entities for shared media (e.g., gaming, white-boarding). IP Multimedia System (IMS) has been the defining factor for emergence and convergence of these applications.  

IMS can be defined as an access agnostic, standard-based IP network that enables the current and yet-to-be-defined applications to be accessed via wireless or wireline networks. The deployment of IMS-capable equipment is the main challenge to both the service providers and the vendors. For the former, piecemeal solutions are not acceptable as they require an end-to-end solution to contain both CAPEX and OPEX (anywhere from 20% to 50% through network simplification and elimination of overlapping IT systems, equipment and labor). For the vendors, providing this end-to-end solution is a challenge as “end-to-end” now has a new definition. It can not only be a horizontal, e.g., end-to-end for a single layer, e.g., transport layer, but it must include multiple planes as shown in figure 1. So in addition to session management, other functionalities that are necessary for complete service delivery are required. Examples are billing, signaling and control plane, security, and roaming. Furthermore, the vendor has to determine what functionalities and features to integrate in one or more platforms to enable a cost-effective solution for its customers.

Figure 1. Horizontal and Vertical Solutions for IP based Fixed-Mobile Convergence

The combination of Ericsson and Redback Networks provide a unique end-to-end solution that covers both the horizontal and vertical requirements of IMS. Specifically, Redback’s SmartEdge Multi-Service Edge Routers provide many of the functionalities that are required in the physical, IP/MPLS transport, subscriber and session managements, bandwidth management, call control and security. The SmartEdge unifies high-performance edge routing, Ethernet aggregation, advanced subscriber management, and advanced services into an efficient, and compact platform. Its bandwidth management and policies capability can be applied to a user’s specific application and individual data streams on personalized basis, and provide the maximum revenue opportunity for the service provider. It is capable of Deep Packet Inspection to identify and process P2P applications, and provide extensive security. stateful Firewall, URL Filtering, and Intrusion Detection/Prevention System (IDS/IPS). Support for applications such as SIP/SBC (session border controller) for IMS and VoIP is integrated into the new SmartEdge controller cards. The SmartEdge also offers differentiated QoS for multiplay applications which is an important feature requirement in the IMS infrastructure.
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Edge Routing capability is supported in hardware with a full suite of IP routing protocols, Multi-Protocol Label Switching (MPLS), with hierarchical Quality of Service (H-QoS). In essence, SmartEdge Multi-Service Edge Router (MSER) is a highly scalable, carrier-class platform that is architected to be a key platform in the deployment of IMS infrastructure. It has redefined the role of an MSER by integrating, critical services necessary for delivery Multi-Play services such as video, voice, data, interactive multimedia content, L2/L3 VPNs whether in a wireless or wireline network. The combination of features and functionality in SmartEdge enables service providers to architect their IMS infrastructure with a minimal number of devices and reduce network and device overlay resulting in simpler network topology and operation.

Since reliability and high availability of IMS platforms are of utmost importance, all SmartEdge MSER interface modules are hot-swappable and highly resilient with full session and state redundancy in the event of a failure or replacement. The SmartEdge uses a highly resilient operating system (SEOS) which is modular and capable of hitless restart. This means that when a software task goes down the system will continue to operate as the task is restarted independently.

The SmartEdge used in conjunction with Ericsson’s IMS solutions can be deployed as the unifying platform for the convergence of wireline and wireless networks in multiple layers with incremental increase in capacity and functionality as necessary.