Maravedis: The coexistence of LTE and WiMAX

By: Robert Syputa, Partner & Strategic Analyst maravedisWireless has now evolved to a more common and overlapping set of technologies and markets such that former distinctions between wireless and wired, streams of standards development including 3GPP and IEEE, and device and infrastructure markets have blurred. Today it is no longer a matter of deciding whether the major industry groups and constituent players should collaborate, but rather how coexistence is efficiently and pragmatically accomplished.

Much work has been taking place within the International Telecommunications Union (ITU), IEEE 802.16e/m, and 3GPP to develop standards for harmonious spectrum access, core network interoperability, backward compatibility, and ease of network and device migration. This work is driven by operators who wish to see a long life for their investments in networks and markets and with suppliers who wish to fulfill the evolving needs of their customers.

A snapshot of current progress:

  • Baseband and integrated chip suppliers have made progress in supplying commercially available ICs and board level products that combine WiMAX and LTE.

          o   Broadcom/Beceem has shown an integrated SoC (BCS500) and USB reference design board-level unit.

          o   Other vendors say they will meet needs of the market with dual-mode capabilities as needed. Sequans was the first supplier of commercial TD-LTE device chipsets and say they are well prepared to meet demands for 4G converged solutions.

  • RF antennas and ICs can accommodate the additional modes needed to combine WiMAX and LTE. Suppliers and operators are now dealing with device and network requirements needed to provide service across 3G, WiMAX, LTE, Wi-Fi, Bluetooth and GPS. Although the growing number of spectrum bands and modes of operation impose increased complexity, WiMAX's similarity to LTE, including use of harmonious or proximity bands, makes coexistence very doable.
  • The standards groups and individual participants have the methods needed to align signaling frame structures between WiMAX 1, WiMAX 2, 3G-LTE and LTE-Advanced networks. Performance trade-offs for frame synchronization are a less than 10 percent hit.
  • The markets have evolved to demand IP-based broadband irrespective of underlying network technology.
  • As 3G core networks have converted to IP, the means to converge more easily with WiMAX has progressed. Obviously, the ease of convergence of operators' networks with LTE or WiMAX depends on the state of their IP network migration.
  • Similarly, subscriber provisioning and billing can be common between WiMAX and LTE. However, incumbent operators must migrate existing networks, if they are not doing so already.

The WiMAX supply ecosystem has evolved to lead LTE development as MIMO-OFDMA technology has emerged to take center stage. As WiMAX has become more mainstream it has entered into more direct competition with traditional streams of development. The broader market opportunities have led to early rounds of consolidation, such as Beceem's acquisition by Broadcom and participation in early LTE product markets, such as Sequan's participation with China Mobile.

An effort is underway by leading WiMAX and LTE suppliers and operators to provide a common framework for 4G coexistence. The work covers both technical and practical aspects of convergence of spectrum plans, networks and baseline service provisioning to accommodate a range of operator needs for integration and coexistence of operations. Companies include Broadcom/Beceem, Clearwire, Huawei, Intel, Samsung, Alvarion, Bridgewater, Cedarcom-Mobi, Comcast, GCT, Motorola, Packet One, Sequans, Tellabs/WiChorus, Vee Time, VITI, Yota, and ZTE. Additional companies have worked on similar alignment efforts, including Nokia, Ericsson, picoChip and Alcatel-Lucent.

The need for operators to find common markets for devices and services that span across 3G, LTE and WiMAX deployments helps to create opportunities that propel development of the commercial products that are now making their way into the market.

It is appropriate to point out that new network deployments, no matter who the operators or suppliers may be, must consider the objectives of reaching common device and market development. The factors of market development often take precedent over the choice of which standard is "winning" the race to become the most ubiquitous way forward. The "best" standard is that which best suits the needs of the operator. This can hinge on maturity and cost of the solution, so long as the evolution of network, devices and market are manageable.

What we think:

We acknowledge that LTE is destined to become the dominant standard for mobile networks. However, the similarities between LTE and WiMAX are due much to WiMAX's pioneering efforts to establish and propel OFDMA as the future for wireless technologies. Moreover, convergence is made feasible due to the enabling of IC and wireless component technologies. Decisions regarding which modes or multiple carrier capabilities to integrate into a common SoC or variety of SDR architectural design approaches are often secondary to questions about developing common spectrum plans and practical aspects of deployments required to build substantial market footprints.  

Operators now deploying LTE must often deal with more pressing difficulties than combining WiMAX and LTE operation: How and when to migrate device markets to multi-mode capabilities; whether to move now to 3G-LTE or wait for LTE-Advanced; how to incorporate IP-based services including VoIP/VoLTE and video services without sacrificing current revenues on the altar of next generation progress. 

We believe that WiMAX and LTE will evolve, as expected, into a growing common market for 4G products and services. While LTE will dominate, WiMAX provides the pedigree of experience and common technology and product development that many suppliers and operators are carrying forward successfully.

Although the leading 3G supplier can be expected to consolidate markets, including the ongoing push toward integrated services, unique opportunities will unfold for companies willing to adapt to mainstream trends. Recent moves by suppliers to provide a pathway to operators for service and supply migration and coexistence heralds inevitable 4G convergence in technologies, products, deployments, and markets.

Robert Syputa is a partner and strategic analyst with Maravedis. Maravedis is a leading analyst firm focusing on 4G and broadband wireless technologies and markets.