WiMAX-LTE Long Term Evolution

WiMAX-LTE Long Term Evolution


The discussion over the role that WiMAX will play in the evolving landscape of the converging wireless broadband industry has been shifting rapidly over the past several months: closer alignment between the rapid development of WiMAX and LTE has been emerging. The question for incumbent operators is more about when a shift to IP networks will make sense and how to convert the prescribed ‘walled garden’ mobile service business model so it doesn't degenerate to selling a wholesale open bandwidth pipe. The question is no longer about ‘if’ but ‘when’ and how to master the now inevitable changes. The way forward is for control of QoS and multiple IP based services and targeted advertising.

WiMAX/802.16 is designed to deliver multiple types and levels of service through a flexible, IP network architecture and authentication and QoS mechanisms. WiMAX can be implemented as a flat, ‘pure IP’ network or as a part of a multi-mode service environment through application servers, network gateways and IMS.

The advance of WiMAX is forcing LTE to the front burner; ahead of IP based services otherwise being solidified within 3GPP, incumbent operators are pressing development of LTE to transition networks so that business models can evolve to deliver premium services and QoS. Incumbent operators have much more to lose besides their deployment investment in NGMN: existing customers and ongoing revenue.

LTE and IMT-Advanced are now headed in a similar direction as WiMAX: Creating networks that are OFDMA based, adaptive to various channels and signal conditions, and is based on standards that are a framework that allows significant change and extension without breaking. This approach now looks obvious.

Admittance of WiMAX into IMT-2000

The admittance of WiMAX OFDMA TDD WMAN (IP-OFDMA) into the IMT-2000 family of 3G standards makes it clear that WiMAX is a cellular wireless system. This includes mobile capability, but like IMT-Advanced and other emerging prescriptions for NGMN/4G, is a scalable framework which can be implemented as a local to metro scale wireless broadband network and for both high value and commodity applications.

LTE is a worthwhile development that the WiMAX cannot argue does not make sense as it copies the objectives and set of technologies. Likewise, WiMAX builds on past success of 3G, lessons learned in how to structure standards, exploratory R&D, and how to construct a development ecosystem. But WiMAX is here now and first to exploit OFDM/OFDMA plus MIMO-AAS in a pure IP wide area, granular network environment.

The big challenge is building sales momentum. LTE has the goal of availability sometime in 2009. However, first commercial availability of LTE to meet ITU IMT-Advanced requirements is expected not earlier than 2011 And to transition incumbent IMT-2000 network spectrum may take several years beyond commercial introduction for either WiMAX or LTE. Subscribers must first transition via multi-mode devices before a hard turnover of network spectrum can occur. That allows both WiMAX time to establish momentum beyond common perception. But this also allows and LTE time to develop together to counter WiMAX’ charge. Transitions of 3G spectrum are unlikely to significantly start until 2012 or later This makes the winning of incumbent operators for deployment of NGMN a long term positioning strategy than with a substantial shift for incumbent deployments a work in progress for several years. That poses LTE more as a paper tiger effort aimed at stalling momentum of WiMAX than forging a near-term shift in market direction from 3G to NGMN/4G.

WiMAX has an image communication problem: The marketing image has not been so well positioned as 'an evolutionary platform'. A lot has to do with the fact that vendors must focus on what can be developed and sold in the near term. But network deployment decisions take long term planning and commitments, making the evolutionary path of development very important.

LTE starts out with the premise that it is an evolution of 3G. This turns out to be more marketing hype than reality: it is not much different from the premise for WiMAX in ability to migrate the user base and supplant existing networks -both WiMAX and LTE are disruptive in their need to convert spectrum and enable a shift to IP centered business models.

There are technical differences between these two: LTE, which will use OFDMA on the downlink and SC-OFDM on the uplink, is optimized for downlink bandwidth and lower power consumption in portable devices. WiMAX uses OFDMA on both up and downlink combined with adaptive power control, modulation, channelization and system architecture to reduce mobile device power requirements. This approach provides more symmetrical bandwidth. The LTE approach assumes that network traffic shows up in the future similar to past experience: downlink to uplink ratios of 5:1 to 3:1. This assumption is being cast into doubt by recent real world experience in 3G data networks. Two thirds of traffic bandwidth as shown from recent network studies by operators is PtP based. Person-to-Person traffic including personal video and file sharing requires more symmetrical bandwidth capacity. This trend likely to continue if not accelerates as new applications such as video conferencing and video posting/sharing come more into vogue. That helps tip the balance in favor of a more symmetrical and distributed technologies and network architecture. Although a wide range of solutions is required, the argument in favor of adaptive use of OFDMA for both uplink and downlink traffic and spatial domain enhancement to both increase capacity and reduce subscriber power requirement is growing.. These near-term technical differences may matter less in the long term to the two sister wireless developments than how business models are developed to use them. WiMAX plunges more directly toward an open IP business model including granular deployment and network segment ownership. 3G-LTE attempts to hold onto the incumbent prescribed service business model. While the two approaches can work together to some degree, longer term the open access IP disrupts the incumbent model.

WiMAX Success in Respect to LTE

Because the technologies and goals are similar, success of WiMAX comes down to execution and marketing and user preferences.. WiMAX is challenging the huge cellular industry for a place alongside it as wireless becomes increasingly a broadband applications platform. But, likewise, the incumbent mobile wireless industry is challenging to become the most personal and leveraged aspect for program applications, content and services for converged wired and wireless network environments.

Shai Yaniv, Sr. Director Corporate Marketing, Alvarion comments that for WiMAX “There is a huge market demand for personal and primary broadband for consumers and households in various regions. WiMAX in the next few years does not necessarily need to address the high vehicular speed applications, which are more associated with voice and audio-visual conversational applications. However, since WiMAX is clearly available before LTE, the time to market advantage WiMAX holds can bring it to fulfill mobile applications in various environments a well. Certainly, the technological capabilities exist and the industry will focus on creating the eco system to help make this happen if the market for WiMAX as a vehicular speed mobile system develops.”

“We should also be looking at the market dynamics with regards to what steps the non mobile carriers and ISPs will take to make space for personal broadband services in their portfolio. Mobile (3G) operators will need to assess their plans as well as considering LTE will not be available soon. This is even more the case for 2G carriers having no 3G spectrum.”

“WiMAX needs to keep up the momentum, particularly on the consumer electronics side which faces challenges leading the industry in use of antenna technologies”, Shai added.


Mr. Yaniv’s comments show both the convergence that is taking place among operator business models and challenges for WiMAX development. Open IP environments are needed to foster common technology development and manufacturing efficiencies but also cast several diverse businesses into competition.

The first task for long-term evolution of the wireless industry has been to construct a flexible framework standard and development environment. The IEEE 802.16 and WiMAX Forum have a significant portion of that work. Evolution of both systems and business models, what can be the more disruptive part still lay ahead

WiMAX has made progress in wireless development and in the perception of what it can deliver and where it is headed. WiMAX is a Long Term Evolutionary wireless platform.