Mobile operators face a huge task: the longterm evolution (LTE) of technology already drives a commercial revolution in the way networks are deployed and interconnected and the way services are launched across them. The strong growth in mobile data pressures operators to invest heavily into network technology again. This whitepaper explains how the BT global IP Exchange can help them seize the Voice over LTE opportunity. BT IP Exchange helps mobile operators accelerate VoLTE deployment
LTE enables mobile operators to reinvent themselves by delivering on the all-ip promise. This evolution is not without major challenges, so picking the right IP Exchange partner can mean the difference between failure and success. Mobile operators face a huge task: the long-term evolution (LTE) of technology already drives a commercial revolution in the way networks are deployed and interconnected and the way services are launched across them. The strong growth in mobile data pressures operators to invest heavily into network technology again. This requirement comes at a time of increasingly saturated markets, disruption from over the top players and regulatory changes driving down margin. On the upside, mobile segments have huge potential: end users ride a wave of new smart handsets and move more and more of their communications onto mobile networks. Mobile network operators need to seize this opportunity by delivering to their end users a customer experience that makes the most of mobility in communication and turns mobile data growth into their business growth. Successful deployment of LTE over individual operator networks is no less important than the interconnection of those LTE networks to support future roaming strategies. BT provides LTE support and roaming capabilities on its IP Exchange to help mobile operators stay successful. BT designed its LTE Roam service to support the roll-out of 4G/LTE roaming to mobile operator end users, triggered by the evolution from 2G and 3G signalling and data roaming to LTE architecture. BT s main differentiator beyond its current and planned service capabilities and a key consideration for LTE roaming customers is its ability to carry huge datatraffic streams cost-effectively across the globe to their destination. BT has more than 25 years of experience in supporting international roaming on behalf of mobile network operators. BT Global Telecom Markets 2
Given the 2G/3G roaming requirements and the limitations arising from expensive roaming data plans, legacy roaming did not require massive long-haul capability. Backhaul requirements focused on the domestic network side. Back-to-home transmissions of data were sufficiently limited to not present a major issue to home users mobile operators. The rise of LTE dramatically shifts the user expectation towards a true super-broadband capability. Because of roaming users, data roaming will create a bandwidth-intense long-haul transmission requirement from roaming networks to mobile operator home networks, easily outmatching traditional transmission arrangements. But with the BT Global IP network and IPX set-up providing end-to-end capabilities across high-capacity links, BT LTE Roam has the power to solve any emerging issues right at the start. It can support class of service from the beginning of 4G data roaming, thanks to BT s knowledge of MPLS architecture to maintain quality endto-end. Moreover, the BT global wifi roaming solution for mobile and fixed operators works with LTE Roam and alongside traditional roaming solutions for 2G and 3G at the BT IP Exchange. Mobile operators gain flexibility by combining all roaming technologies through a single interconnection in a onestop approach. The resulting simplified technical and commercial set-ups will lower cost and enhance the opportunity to deliver new, innovative services. BT LTE Roam The LTE Roam service enables roaming for obile operators and mobile virtual network operators (MVNOs) over a single IP Exchangebased connection for 3G and 4G services. The signalling is Diameter based and covers all variants. The data roaming capability encompasses GRX and 4G with class of service and includes connectivity between home and visited networks. Significantly, BT LTE Roam assists in providing interoperability between the variants of the Diameter protocol. This includes plans for Sigtran-to-Diameter conversion on the platform. The service consists of a global network of Diameter edge routers and nodes located in Europe, the Americas and Asia Pacific. There is no single point of failure on the BT LTE Roam network, which offers multiple access options including telehouse cross-connect, internet and GSMA standards compliant access through the BT MPLS network in more than 180 countries. LTE Roam provides access to 3G and 4G data-roaming networks worldwide via peering with other GRX and IPX providers, and via directly connected LTE networks as roaming is launched. This means simplified, competitive customer friendly one-stop roaming with the intention to offer global access to any LTE network that has launched roaming services. BT Global Telecom Markets 3
The HD voice opportunity High-definition (HD) voice is the first of many new value-added interconnection services. It turns the IPX into a vital platform for operators that are looking to differentiate, decrease churn, and grow their reach and revenues. Industry analysis shows that HD calls last longer, thereby increasing revenues. By June 2014, HD voice had been launched by 109 mobile operators in 73 countries, according to the Global Mobile Suppliers Association (GSA). But the environment is still fractured and, because a variety of protocols are used, interworking is complex. Replication of traditional roaming agreements would be time consuming and expensive, so BT is helping to bridge the gap between pure internet and network-based services by aggregating calls among the operators involved. It is opening up new routes for HD services by providing cross-network connectivity, supporting seamless signalling protocols and offering intercodec conversion and quality of service through transcoding and tran- BT Global Telecom Markets 4
Gearing up for VoLTE Mobile operators are now starting to aggressively roll out Voice over LTE (VoLTE) services, where HD voice is the default codec. The GSA, as of June 2014, is estimating that there are 52 mobile operators in a variety of stages of deployment of VoLTE. And they are rolling it out for very good reasons. With the evolution of 2G and 3G data services, voice remained largely circuit-switched, creating a significant asset legacy retained by the mobile operator to ensure high-quality voice services that the end users are critically dependant on. The resulting revenue streams still form a key element in each mobile operator s strategy. With the explosive growth in data traffic and a resulting need for investment in LTE, voice and data are drifting apart in terms of a commercial strategy. Consequently, migrating voice to LTE would offer significant cost savings for a number of reasons: First, the bandwidth requirements of voice represent less than 1% of all traffic. LTE network build-out will accommodate it without additional investment. Second, reducing traditional circuit-switched technology in the medium term (rather than long term) subtracts complexity and legacy cost and lowers end-of-life investments. Third, this migration could free precious spectrum to reapply to the long-term evolution to 4G and inevitably 5G down the road for significant cost saving and efficient use of limited resource. And fourth, VoLTE provides quality of service capabilities so the mobile operator can offer a consistent and excellent customer experience versus the best-effort service from OTT providers. Voice over LTE also seeks to enable more featurerich services in the mobile network. These include highdefinition voice, video calling, high-definition conferencing and rich communication services (RCS). They are all more bandwidth hungry than traditional switched voice. The move to host voice as a service on data-packet LTE cores instead of legacy-switched cores makes these services commercially viable. From a roaming perspective, VoLTE provides operators with new challenges. VoLTE domestic networks have to be interconnected with those thirdparty mobile operators sending their end users roaming into a given mobile operator s home network. As international travel continues to grow, this will drive an increase in data-roaming traffic. At the same time there is regulatory pressure to improve the customer experience through lower prices, and fierce competition is in play in saturated mobile markets. These factors combine and lead to one paradigm: A positive LTE end-user experience must not stop at the mobile network border. Otherwise users will readily switch to OTT players and use public wifi as a bandwidth substitute whilst travelling thus pulling their usage and business away from the mobile operator. So the mobile operator needs to ensure that their end users can find and exploit LTE networks wherever they travel. This adds complexity to traditional roaming, but it also introduces the already mentioned long-haul traffic demands that need to be addressed. And as LTE-enabled VoLTE features like high definition voice, video calling, conferencing and inevitably RCS require service-based interconnect capabilities like transcoding, transrating and end-to-end quality control on high-volume data transmissions complexity mounts again. This is the point where support is needed, and the BT IP Exchange is set up to provide it, through a complete solution for mobile operators: LTE Roam delivers an LTEbased roaming framework, taking the complexity away even as LTE roaming coverage grows and IP Exchange extends mobile operator reach. The high-definition voice capabilities ensure that all transcoding, transrating and call handling for VoLTE across networks are managed. BT High Definition Voice support even extends onto fixed and OTT networks, broadening mobile operator reach again and maintaining the high-fidelity experience end-to-end. With the BT global IP network, the capacity to haul traffic across regions is in place, combined with regional network intelligence as self-federated IPX nodes break out traffic where appropriate. In this way, mobile operators can stay compliant with relevant standards and benefit from an all-ip global environment. But the key point in the BT interoperability framework is the pragmatic design for service, change and growth. Rather than providing a limited signalling framework, the BT IP Exchange is built for commercial delivery and flexible service innovation. Its power lies in its ability to combine services, from voice, roaming, and value-added services to wifi and future applications. Its global reach, with more than 400 customers connected and the volumes of their live traffic, show that this is a commercially successful service. For MNOs, picking the right LTE roaming and IPX partner can be decisive. BT is positioned to help them succeed in their long-term evolution, technologically, and most of all, commercially. www.bt.com/globaltelecom BT Global Telecom Markets 5
Offices worldwide The telecommunications services described in this publication are subject to availability and may be modified from time to time. Services and equipment are provided subject to British Telecommunications plc s respective standard conditions of contract. Nothing in this publication forms any part of any contract. British Telecommunications plc 2012 Registered office: 81 Newgate Street, London EC1A 7AJ Registered in England No: 1800000 GTM-ONE-ADV-2014-001-002