All Roads Lead to Rome: The Migration to the Next Generation of Mobile Networks

This article originally appeared in the Feb. 2012 issue of Next Gen Mobility

Many mobile network operators currently regard the so-called 4th Generation (4G) of mobile networks to be the center, the “Rome”, of the mobile world. The performance promises made by this new generation are tempting lures for customers. So it is no wonder that so many operators are in a hurry to hit the road in the direction of 4G.

There has been considerable dispute about whether specific technologies can truly claim the 4G label or not. Here, we consider 4G technologies as mainly characterized by their optimization for efficient support for data-based services and applications. While WiMAX (News - Alert) was seen at the pole position for some time, it has now been mostly overtaken by LTE. For this development, the performance of both technologies in terms of isolated parameters such as maximum data rates was less significant. The industry support and the overall system concept are much more important for network operators. This is where LTE (News - Alert) and WiMAX differ decisively. Along with LTE, a complete network architecture, ranging from mobility management to billing procedures was specified. Also the interoperation with other technologies was considered comprehensively. Thanks to this a step-by-step migration becomes feasible and investments can be confined to local areas for the operators of existing GSM, UMTS, and even CDMA networks. General opinion is that WiMAX will play nothing more than the role of a limited-territory substitute for wired connections to the Internet.

In the relatively rare case of network operators who have no infrastructure in place and who want to offer a data only network, there will be a chance for WiMAX. However, economies of scale resulting from the anticipated greater market growth of LTE will make LTE more and more attractive. Some of the current WiMAX network operators already think about a transition to LTE in the mid-term. For voice support and a comprehensive portfolio of end devices, the most likely first step is currently a combination of UMTS and HSPA+.

If there is an existing network and interoperability between 4G and the existing access network is intended, LTE is the most capable choice due to the standardized interworking features. For providers who have been offering GSM/GPRS only, there is the choice to leap over 3G and implement LTE for mobile data services right away or to take the intermediate step using 3G and HSPA+. Such an interim step requires investment into an additional technology implementation, but it offers the advantage of an extensive portfolio of end devices available right now. Most of the popular smartphone models do not yet support LTE today. The line of 4G products will expand steadily, but for a long time the choice of models will not come even close to what is there for 3G and will be aimed primarily at the high-end market.

Some critical aspects that network operators should consider in advance of a 4G migration are related to the fact that 4G introduces a consistently IP-based concept. While this brings an efficiency increase, it also requires network operators to think about new challenges. One of these is the potential vulnerability of the network to hacker attacks, which requires a sophisticated security concept. There will be also an increased pressure to migrate to IPv6 to satisfy the high demand for IP addresses. This alone is a highly complex endeavor. A third aspect is the support of voice telephony. Voice was not really considered as a service for WiMAX. For LTE, voice support over the IP network has been built into the standard, but solutions are not yet available. Meanwhile,fall back on the 2G or 3G network for the voice service – if it exists – is the only alternative but has different drawbacks. The initial lack of voice support as well as the focus on IP-based services also increases the risk for operators that they will be relegated to data pipes for higher value services offered via Internet platforms.

The target 4G mobile network for most established network operators will be LTE (including its evolution LTE Advanced). In the medium term, WiMAX will be confined to a niche existence. HSPA+ will be a feasible interim solution for a longer time, especially in less developed markets, and complement the spread of LTE. The best route toward the introduction of LTE must be identified by network operators according to their own specific circumstances.

Arne Chrestin and Andreas Schieder are managing consultants for Detecon International (www.detecon.com).