Why is LTE going to win over WiMAX?

After that Qualcomm, in November 2008, announced it was ending development of the Ultra Mobile Broadband (UMB) technology favoring LTE instead, LTE and WiMAX are the only two technologies that are competing to become the most widely adopted standard for 4G networks. WiMAX refers to the IEEE 802.16 family of standards which include notably IEEE 802.16-2004, the first major WiMAX standard for fixed access. This was superseded by IEEE 802.16e-2005, known as Mobile WiMAX, which provides both fixed and mobile access. In October 2009, the IEEE 802.16 Working Group submitted its proposal for IMT-Advanced based on IEEE 802.16m, which enhances IEEE 802.16e-2005 to meet the IMT-Advanced requirements. Although WiMAX benefits from its earlier development and deployment and today it has about 519 deployments worldwide with more than 10 million subscribers, LTE has quickly gained substantial momentum and it is expected to surpass WiMAX and become the accepted standard for 4G systems. This common thinking is supported by the Wireless Market Research and Analysis’ (Maravedis) forecasts which estimate 75 million WiMAX subscribers by 2014 while over 200 million LTE subscribers by 2015. It is also expected a migration of WiMAX operators towards LTE anytime before 2013. The aim of this post is to explain the reasons why LTE is going to win the “4G-battle”.

- LTE vs WiMAX performance

Table 4 shows the main technical specifications for WiMAX and LTE.

Table 4: LTE and WiMAX technical specifications

The performance of LTE (3GPP Release 8) and IEEE WiMAX 802.16m are similar in both data rates and latency, and mobility support. It is worth mentioning that both LTE and WiMAX use OFDMA in the downlink, but they differ in the uplink. WiMAX continues to use OFDMA, while LTE’s approach (SC-FDMA) is more advanced and allows a reduced peak-to-average ratio (PAPR) for the uplink signal. This makes it easier for the mobile terminal to maintain a highly efficient signal transmission using its power amplifier.

At the moment, 3GPP is working on LTE-Advanced (3GPP Release 2010) which promises further better performance and this is a clear advantage of 3GPP over WiMAX.

- Industry Support

The main difference between LTE and WiMAX is that they are supported by companies specialized in different fields. WiMAX supporters are mainly computer companies such as Intel and Cisco and there is a waning support from telecommunications companies. At the moment Sprint and Clear are the biggest service providers that have shown their commitment to WiMAX, while Samsung is the main smartphone manufacturer. On the other hand, as we saw in the previous paragraph, 3GPP counts more than 350 individual members, including major service providers, vendors, chipset providers, User Equipment (UE) providers, and test equipment vendors. Moreover, a strong confidence of service providers towards LTE arises from the close cooperation of 3GPP with NGMN alliance for defining the requirements of the standard and with LSTI for collaborative technology trials. As result of this cooperation, in July 2008, NGMN approved LTE as it first compliant technology, instead of WiMAX. Hence, since LTE was developed with support of the major mobile operators in the world, we can aspect that the great majority would adopt LTE, and not WiMAX.

- Evolution from previous standards and interoperability

LTE comes form the 3GPP organization. An organization which has acquired broad confidence among users, vendors and service providers with GSM and UMTS. On the contrary, WiMAX comes from an industry association, which is quite new in the cellular networks. As a consequence, service providers and vendors are inclined to evolve their system from UMTS towards LTE instead of adopting a completely new standard. Moreover, LTE provides seamless integration with 3GPP-based 2G/3G networks and with 3GPP2-based 2G/3G networks and provides seamless handoff to CDMA/1xEV-DO. This interoperability capability of LTE with legacy systems is attractive to such providers as this will allow them to roll-out their LTE network in several phases without interrupting their existing services.

- Smartphone manufacturers

Along with the mobile operators, also the smartphone and laptop manufacturers play an important role in the battle of 4G. Indeed, end-users will go for handsets with the coolest factor. The iPhone completely changed the way we look at mobile phones and what we expected from such devices, and it has contributed to increase exponentially the 3G data traffic generated by the mobile users. The continuing commitment of Apple in developing devices that only support 3GPP standards suggests that the successor of the iPhone 4 would probably support LTE standard. As Apple, other popular devices only support 3GPP standards, driving non-3GPP networks based service providers to converge to the 3GPP standards.

- Result of the battle

From this analysis LTE has emerged as the favourite winner of the “4G-battle” and in the following years it will become the most widely adopted standard for 4G mobile communications. On the other hand, WiMAX will not disappear, indeed it has been targeting emerging markets that have little infrastructure, because WiMAX deployment would be faster and more cost-effective than laying a wired infrastructure. But we will see a migration of WiMAX operators towards LTE.