The so-called battle between Long-Term Evolution (LTE) and WiMAX for 4G cellular service, if there ever was one, was decided some time ago. Most of the world’s carriers selected LTE for their 4G cellular systems. A few selected WiMAX. Sprint and Clearwire selected WiMAX and are now bringing it online. AT&T, Verizon, and T-Mobile are going with LTE, but it is taking some time. Verizon will implement LTE later this year, though a full rollout will take years.

At the recent CTIA Wireless conference, Bill Morrow, CEO of Clearwire, indicated that the company was agnostic as far as wireless technology goes. It chose WiMAX because it was a final standard and relatively inexpensive and available, unlike LTE. But what if Clearwire decides to change to LTE later? Or what if Verizon or AT&T decides to move from frequency division duplexing (FDD) LTE to time division duplexing (TDD) to conserve spectrum space and expand capacity? Massive problem? Not really, especially if the equipment uses chips like Wavesat’s Odyssey 9010.

The Odyssey 9010 wireless baseband chip supports both LTE 3GPP Release 8 (both FDD and TDD) and WiMAX IEEE 802.16e Wave 2. After all, both technologies are based on orthogonal frequency-division multiplexing (OFDM) versions that are quite similar. It is possible to make a baseband chip that can do both. In fact, the Odyssey 9010 can seamlessly switch from FDD to TDD or from WiMAX to LTE on the fly if roaming encounters such changes. A handset with an Odyssey 9010 would be enabled for these switches.

The chip’s unique hybrid architecture incorporates a combination of highly efficient DSPs and hardware acceleration blocks that easily scale from the standard 100-Mbit/s downlink and 50-Mbit/s uplink to support devices with data rates up to 150-Mbit/s downlink. The Odyssey 9010 targets 4G USB dongles, data cards, mobile handsets, and mobile Internet devices (MIDs), offering full programmability and low power consumption.

Further, the chipset supports both TDD and TDD schemes and comes complete with an LTE protocol stack including MAC, RLC, PDCP, RRC, and NAS layers. Reference design kits for manufacturing dongles and customer premise equipment (CPE) are also available. Now, Wavesat needs to make this chip backward-compatible with 3G networks using WCDMA, HSPA, and EV-DO.

The Odyssey 9010 has been sampling since the fourth quarter of 2009 and has gained wide acceptance. Alpha Networks of Taiwan selected it for deployment in its forthcoming LTE networks. Wavesat also recently partnered with picoChip for LTE demonstrations and testing. The goal is to test the over-the-air interoperability between picoChip’s eNodeB basestations and Wavesat’s user equipment (UE) handsets with both TDD and FDD modes on a range of E-UTRA bands.

While Wavesat was the first to package both LTE and WiMAX in a system-on-a-chip (SoC), Beceem’s BCS500 combination LTE/WiMAX multi-mode chip supports the latest revisions of the IEEE 802.16 standard, namely 16e and 16m, as well as the 3GPP-LTE standard, based on Release 8 specifications. It also supports UE Class 4 capabilities in addition to TDD and FDD configurations for LTE and IEEE 802.16m. This enables real-time band/channel reconfiguration through a unique multi-mode “autosense” feature that automatically detects the network type.

The Beceem 4G-LTE/WiMAX chip supports up to 150-Mbit/s downlink speeds. With its ability to connect to any 4G LTE or WiMAX network with seamless roaming, and switching between TDD and FDD configuration as needed, it frees operators from concerns of how best to use their valuable spectrum.

Beceem

Wavesat