VoLTE Operators Need to Balance Offload with Signaling

LTE users are consuming 10 times as much data as other network users

More people than ever are using 4G-LTE networks, and this influx of smart devices, machines and appliances connected to the Internet will cause extra traffic, and strain the capabilities that draw consumers to a new network in the first place.

By 2017, according to a recent report by Pyramid Research, the number of LTE subscriptions worldwide will reach 802.2 million, a 72% CAGR over 2012 levels, growing to almost 10 percent of global mobile subscribers.

These users want fast, widespread services to support calling, Internet and flashy apps, and they’re intolerant of interruptions and latency. This is of particular concern as Verizon, T-Mobile and other carriers announce plans to roll out voice-over-LTE (VoLTE) within the next year. If VoLTE is to live up to its promise – clearer calls and simultaneous voice and data – carriers will need to protect LTE from the slowdown that plagued earlier networks.

LTE networks might be 10 to 20 times faster than 3G networks, but the ever increasing number of smart devices, M2M communications, data usage and VoLTE calls could eventually bring that speed down significantly, threatening network functions and capacity. Users of the new iPhone 5S, for example, are reportedly eating up at least seven times more mobile data than iPhone 3G users. Operators suspected this outcome; they knew if they built fatter pipes, customers and mobile device makers would find ways to fill them.

Wi-Fi offloading, telecom signaling key to bright LTE future

Wi-Fi offloading in the U.S. rose by 875 percent in 2013, as operators tried to keep more data-hungry smart devices from slowing LTE networks. By enabling roaming onto Wi-Fi, service providers meet customer demand for service availability without burdening their LTE networks.  With more than 207 million global Wi-Fi hotspots, offloading is a viable means of satisfying customers who want the most services at the lowest possible cost.

This represents an opportunity for Wi-Fi providers and mobile network operators (MNOs), who are offering complementary Wi-Fi networks as a means of expanding their coverage areas, decreasing costs and improving network functions. Through roaming agreements, MNOs and wireless operators get better returns on their network investments, and their customers get consistent service.

Interworking guidelines set the stage for seamless user experience

Wi-Fi offloading eases the burden on LTE networks, but it requires carriers to interwork from one type of signaling to another without users noticing any interruption to service. That’s because LTE relies on Diameter signaling, 3G relies on SS7 signaling and Wi-Fi relies on RADIUS signaling for subscriber authorization, authentication and accounting. Therefore, carriers need a process for moving from one to the other in order to keep Wi-Fi offloading seamless, billable and attractive to smartphone users.

There are several things service providers can do to protect VoLTE and other user experiences on modern networks. They can:

  1. Offload data usage to Wi-Fi networks to ease the strain on LTE;
  2. Follow the roaming guidelines produced by organizations such as the Wireless Broadband Alliance, GSMA and 3rd Generation Partnership Project;
  3. Improve interworking between Diameter and other signaling protocols; and
  4. Keep the user experience seamless across Wi-Fi, 3G and 4G networks through roaming.

Roaming guidelines from several industry groups should make this interworking easier. The Wireless Broadband Alliance (WBA), for example, gives its member operators a reference point as they begin to work on roaming solutions, and Wi-Fi operators have several choices when it comes to putting systems in place. Operators can either connect directly with each other to form roaming partnerships, or they can go through third-party internetwork packet exchanges (IPX) with a wireless roaming intermediary exchange (WRIX) in order to roam across Wi-Fi.

The 3rd Generation Partnership Project (3GPP) also has specifications, which are geared toward Global System for Mobile Communications (GSM) operators. These outline how Wi-Fi networks can integrate with 3G and 4G mobile networks to create benefits for users and operators. The GSMA and WBA are working together to streamline adoption of Wi-Fi roaming and to make the integration of 3GPP mobile and Wi-Fi seamless. Both paths are crucial to ensuring smooth interworking between RADIUS, Diameter and SS7/MAP interfaces, thereby protecting LTE networks from excessive traffic.

LTE subscribers push the boundaries on ‘seamless’ capabilities

LTE users are consuming 10 times as much data as other network users, and it could be only a matter of time before the fat pipes of these new networks become as clogged as the previous infrastructure they were designed to replace. The best defense operators have against that possibility is Wi-Fi offloading and signaling interworking. This is particularly important today, as operators expand into VoLTE services, and consumer expectations for service and availability continue to escalate.

About the author:

Jim Machi is vice president of product management at Dialogic, responsible for driving the overall roadmap and product strategy. Machi holds an MBA degree from New York University’s Stern School of Business and a BS degree in electrical engineering from the University of Pennsylvania.

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