Enabling Roaming Across LTE Networks

The mobile operator community is working to address the increasing need for bandwidth that accompanies the rollout of next generation 4G networks. These Long Term Evolution (LTE) networks pave the way to full IP convergence, which operators see as a key to enabling accelerated time-to-market of new services that can drive customer satisfaction and generate new revenues. 

The mobile operator community is working to address the increasing need for bandwidth that accompanies the rollout of next generation 4G networks. These Long Term Evolution (LTE) networks pave the way to full IP convergence, which operators see as a key to enabling accelerated time-to-market of new services that can drive customer satisfaction and generate new revenues. 

As operators launch LTE services in their home markets, consumers will naturally expect the same quality experience everywhere — even when they are abroad. In view of this requirement mobile operators that deploy LTE networks in their domestic markets are starting to review options available to ensure LTE services allow seamless roaming overseas. 

The first users of LTE will typically be VIP customers or key corporate accounts, a segment made up of high-end users and frequent travelers. To serve these premium customers, and the proliferation of data services and smartphones, operators will need to address LTE roaming requirements sooner, rather than later. 

Prepare for roaming

New services on LTE networks, such as video streaming, HD voice and Voice over LTE applications, put high demands on the data roaming backbone and require much more bandwidth and resilient network connectivity. As mobile operators review their LTE roaming connectivity options, they will need to consider the following business and technical factors: 

  1. Diameter Signaling The build out of high-speed LTE networks is different from the technologies that preceded it. LTE requires a completely new signaling protocol. Put another way, SS7 MAP— which has been the standard for 2G / 3G mobile networks — is no longer needed. A new signaling protocol has been introduced, called Diameter.
  2. New Roaming Connectivity Agreements In a roaming environment, the existence of this new protocol will require mobile operators to establish new roaming connections. As operators launch LTE networks over the coming years, new roaming connectivity will be required with each new operator. Effectively, the work performed over the last 10 years will need to be repeated.
  3. Diameter Relay Agent To enable this connectivity, operators will require a Diameter Relay Agent (DRA). In the initial build out of LTE networks, the majority of mobile operators have not deployed a DRA into their networks. Operators are facing challenges of the immediate business requirements to enable LTE roaming versus the need to obtain CAPEX budget approvals to acquire the required DRA equipment.
  4. An IPX Provider It is widely accepted that LTE roaming with Diameter signaling will be connected across Internetwork Packet Exchange (IPX) networks. As LTE roaming proliferates, there will be a need for IPX providers to enable peering both at the data level and at the signaling level. Consideration will also be needed to ensure Quality of Service (QoS) SLAs are implemented. Important choices In the new LTE world, mobile operators will have a choice: they can work with LTE roaming hubs, or they can directly connect with mobile operators. The “hubbing” concept is not new to the industry. There is a wide variety of these — including iSMS hubs, iMMS hubs, roaming hubs and clearing hubs — and all fulfill a similar role. Depending on the operator requirements, hubbing allows them to reach operators with one-to-many connectivity, reduce efforts and testing time, accelerate time-to-market for services and facilitate transaction settlements between operators. 

In the LTE roaming environment, mobile operators can connect to an LTE roaming 136 hub, a hub that will also facilitate connectivity to the wider operator community made up of operators that also connected to the same hub.

To facilitate active deployment for mobile operators, the LTE roaming hub will also need to provide an outsourced DRA capability running on the hub itself. Operators have the option to utilise this outsourced DRA capability immediately to connect to roaming partners.

This may sound easy, but, as the industry has experienced through operator trials, interworking with suppliers’ DRA equipment can be challenging. Whilst specifications are defined for the Diameter protocol, unique supplier variations are evident and require mapping to enable seamless interworking.

In the initial stages of LTE roaming deployments, it is likely operators will facilitate their connection via an LTE roaming hub. The business benefits delivered by this approach are as follows: 

  1. Immediate time-to-market. This equips operators to deliver an immediate service to their high-value customers.
  2. Cost effectiveness. Whilst LTE roaming capability will be key, network rollouts will take time and the number of roaming users to start will be low. Mobile operators can generate revenue from their initial rollouts through an LTE roaming Hub.
  3. Technical readiness. Many operators are missing a key technological component, the Diameter Relay Agent. An LTE roaming hub — which offers an outsourced DRA capability — will enable operators to move forward with an LTE roaming solution.

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Matthew Tonkin oversees SAP Mobile Services’ global GRX/IPX/LTE Roaming business. In addition Tonkin is responsible for managing and driving the company’s growth and market leadership in both Enterprise Services and Mobile Operator Services businesses across the AsiaPac region, through a combination of direct sales and a partner & alliances sales network.

This article is a sample article from SAP Mobile Services’ first-ever “Mobile Operator Guide 2013: The Evolution of Mobile Services: Challenges, Strategies, Opportunities.” The complete Guide can be found here.