LTE rollout poses several challenges

Rolling out LTE networks is not enough to accommodate the surging demand for bandwidth. Service providers need LTE solutions that can scale to handle millions of devices and subscriber sessions, as well as provide end-to-end visibility into the network.
Such solutions also must enable service providers to manage network resources, reduce operating expenditures, and create new revenue streams by monetizing the data traversing their networks. Equally important, such solutions must improve the subscriber experience on the network.
Mobile networks will continue to be a mix of 2G, 3G and 4G technologies for years to come. Consequently, service providers need an LTE build-out strategy that makes possible the delivery of new high-bandwidth services while also paving a smooth migration path for non-LTE subscribers.
Without a separate diameter signaling infrastructure at the network core to support signaling between network elements, endpoints such as mobility management entities and home subscriber servers must use direct or point-to-point signaling connections to each other. In the resulting mesh-like network architecture, network endpoints must handle all session-related tasks such as routing, traffic management, redundancy, security and service implementation. Implementing an IMS or LTE network without a signaling framework may suffice initially, but as traffic levels grow the lack of a capable signaling infrastructure creates a chaotic mesh.
Policy charging and rules function (PCRF) binding is yet another challenge. When multiple PCRFs are required in the network, there is no way to ensure that the same PCRF processes all messages associated with a given user’s session. By contrast, a centralized signaling architecture addresses issues such as connection management, fault handling and interoperability.
Currently, subscriber data is stored in many different locations, typically defined by different access technologies and/or the applications that require the data. The combination of non-traditional competitors such as Skype and Apple, the widespread use of smartphones and other devices, the personalization of subscriber services and the deployment of all-IP networks are forcing service providers to re-think how they manage subscriber-level data.
Recognizing the need for consolidated data, the 3GPP took a step toward improving SDM when its members adopted the user data convergence (UDC) standards. Unlike traditional SDM platforms, next-generation solutions eliminate silos altogether. Data is no longer duplicated, and application front-end nodes can extract the data they need from a single, highly-scalable relational database.
As the industry rapidly develops the ability to deliver any service over a single, next-generation broadband network, service providers must satisfy the relentless demand for richer, more bandwidth-intensive content and applications while also controlling their network-expansion costs. They must also differentiate services, maintain a consistent quality of experience (QoE) and generate new revenue.
Policy management helps by managing bandwidth and other network resources to handle traffic growth efficiently. When used in tandem with a next-generation SDM solution, it provides a single cross-domain view of the subscriber profile, enabling the service provider to verify subscriber identities and streamline service delivery.
Common uses like service tiering and subscriber personalization enable the operator to capture larger and more diversified segments of the market. Policy management solutions can boost ARPU by making it possible to offer opt-in high-quality/premium services, such as high-definition video and multimedia communications. Ultimately, such capabilities create a stickier relationship between the service provider and subscriber and thus reduce churn.
To be most effective, policy control must be dynamic so service providers can manipulate services as often as they deem necessary. As service providers and their subscribers migrate to LTE networks, what subscribers use, how much they use, where they use [it] and how much they pay when they use it can change daily or hourly.
Examples of policy management use cases are supplying bandwidth on demand, mobile video, and M2M.
End-to-end visibility
The ability to deliver a consistent high-quality customer experience is a competitive differentiator and depends on the service provider's ability to constantly monitor the performance of the network and services, as well as collect important data.
For example, say a passenger in a car wants to use a navigation application on her smartphone to locate a restaurant. To deliver this [function], the service provider requires mobility management via Diameter, session management, location-based services, and web protocols such as HTTP. If any of these underlying functions performs incorrectly, the end-to-end QoE will be poor despite all of the other services working fine.
Another consideration is that not all customers are equal in the eyes of the service provider. Mass-market subscribers may be willing to accept best-effort video streaming and bandwidth-throttling during peak usage times, but enterprise subscribers are likely to demand a consistent QoE at all times.
Managing this QoE involves virtually every part of network operations and it presents several challenges. For one, service providers need to monitor legacy and next-generation networks simultaneously to determine in real time the status of the entire network. Also, the performance-management system must handle all protocols across various network types. And for troubleshooting, operating systems must support end-to-end multi-protocol call segments as well as call tracing.
The migration path to LTE is studded with obstacles, but service providers can execute the successful transition if they incorporate in their strategies a scalable control plane, non-siloed subscriber data management, dynamic and centralized policy management, and QoE management.
Jason Emery is director of product management at Tekelec. For more information visit