dailywireless.org » Mobile WiMax: It’s Done

Mobile WiMax: It’s Done

It’s done. A mobile WiMax standard has been approved by the IEEE.

Mobile WiMax (802.16e) was designed for city-wide metro area networks. It combines WiFi speeds with cellular range using the 2.3 Ghz, 2.5 Ghz, 3.5 Ghz (licensed) and 5.8 Ghz (unlicensed) bands. Beceem, a mobile WiMax chip developer says a mobile WiMax (OFDMA) network provides up to 35 percent better performance than a current-generation 3G network in similar frequencies and channel widths.

Mobile WiMax delivers more bits and has more options for handling bad connections than cellular’s latest - HSDPA or CDMA Rev A. It plugs into Ethernet - like WiFi. It supports roaming voice and high speed data - like cellular - in both licensed and unlicensed bands. Intel loves it.

The new Mob i le W i Max standard will be published as 802.16e-2005, not 802.16-2005, which is reserved for a full revision of .16, something not forthcoming this year.

Approval by the IEEE’s Standards Board was expected since the 802.16e spec was finalized two months ago, but the formal announcement brings the advent of mobile broadband a significant step closer, explains CommsDesign. Om Malik and EE Times have more.

Mobile WiMax trials and certification testing are expected to start in the first quarter of 2006, organized by the WiMax Forum. Products will likely follow late 2006 and services by early 2007, says CommsDesign.

The formal announcement Wednesday (Dec. 7) brings to a close the work of a 802.16 Task Group and its project that began with the approval of the original 802.16e spec in December 2002.

Roger Marks, working group chairman, said:

“We projected completion in about 18 months. Actual development took about twice that long. Though we all would have preferred to stick closer to schedule, the reality is that the working group changed dramatically during those years.”
“I am proud of the fact that we addressed all of the resulting needs, continuing to harmonize and build consensus to ensure a result with broad support and broad applicability.”

Standardization of 802.16-2005 is vital. That’s because Mobile WiMax roams. Different transmitters must be able to communicate with different receivers. Fixed gear doesn’t have those issues.

The key difference between the fixed and mobile WiMax standards is a more-efficient S-OFDM modulation sceme. S-OFDMA (Scalable orthogonal frequency division Multiple Access) can assign a subset of sub-carriers to individual users. By using different subcarriers multiple people can connect at the same time on the same frequency without interference.

The number of subcarriers can be adjusted dynamically adjusting for different bandwidths and conditions. For weaker indoor reception, a Mobile WiMax client might ratchet down automatically, using fewer (but stronger) subcarriers with rugged QPSK modulation.

The Korean WiBro standard was largely developed around SOFDMA. The IEEE believed the advantages of Scalable carriers and subchannels were so compelling they adopted it despite the fact that it “broke” compatiblity with the original 802.16-2004 standard.

Wavesat’s Chief Scientist, Dr. Jonathan Labs will oversee 802.16e compatibility with 802.16-2004 deployments. The 802.16e OFDM Evolutionary Taskgroup is addressing compatibilty with 802.16-2004 via subchannelization and support for a gradual shift to 802.16e.

Supporters of 802.16-2004 believe the fixed standard will be sustained by laptop-based WiMAX cards, before 802.16e arrives.

Handoff was a challenge. Cellular-based standards have the advantage of many years experience in handoff. Mobile IP, with “slow” handoff, is fine for web-browsing but not enough for decent voice. Many services require the appearance of seamless connections (VoIP, VPNs, etc). Much of the complexity (and latency) on cellular networks is from maintaining these connections across cell boundaries.

A better link margin, support for mobility, improved indoor coverage, flexible management of spectrum resources, and a wider range of terminal form factors are some of the advantages offered by 802.16e over the earlier fixed 802.16-2004 (pdf tutorial).

A WiMAX Forum White Paper says adding subchannelisation, MIMO and beam forming to a base station could increase coverage from 2km to 9km, a twenty-fold increase in coverage and subscribers. Consequently, most operators are expected to “standardize” on Mobile WiMax, despite its extra cost and complexity.

Vendors are expected to begin embedding WiMAX chips directly into laptops in a couple of years. Sequans and Telecis plan mobilized WiFi/WiMax chipsets next year.

The WiMAX Forum has not yet announced the frequency bands for the 802.16e profiles, but 2.3 GHz and 2.5 GHz are the most likely initial candidates. Certification is expected to start in the middle of 2006 when the certification labs open, with the first certified products available in the first quarter of 2007.

The link budget defines cell phone range. In general terms, cell tower capacity of 100 simultaneous users must install more towers to increase capacity. WiMax, with 10 times the capacity of 2.4 Mbs cellular, needs fewer towers for data-intensive applications or in dense urban settings.

Cellular companies often occupy paired 10 Mhz PCS spectrum (at 1.9 Ghz) using sector channels that are 1.25 or 5 MHz wide. Sprint, on the other hand, may use Mobile WiMax on simplex 10 MHz sectors (at 2.5Ghz). Clearwire and BellSouth could offer (limited) competition to Sprint in the United States. The unlicensed bands are unlikely to be big factor in Mobile WiMax (until gear gets cheaper) due to range limitations. IP-based WiMax gear will likely be cheaper than cellular equipment and easier to setup (with Ethernet).

While it’s just speculation, the real revolution may happen in 3-5 years. That’s when $200-$500 WiMax access points, using the unlicensed 5 Ghz band, could be in electronic superstores. “Pre-certified” gear could arrive sooner - perhaps a year or two - if history is any indication.

WiMax is not just a good idea — it’s the law. Phone and cable companies can now lock out competing ISPs like Earthlink. Telcos now want to “priortize” access to websites. WiMax provides (some) competition for ISPs who would otherwise be shut out and shut down.

Mobile WiMax (802.16e) is on the move:

BellSouth and Navini are providing Pre-WiMax In Athens GA as well as New Orleans and other citys in the Gulf Coast. They’ll use Navini’s Ripwave-MX dual-mode CPE, which starts shipping in Q4 2005, and the Ripwave-MX dual-mode PCMCIA card targeted for 1Q 2006, will both be software upgradeable to Navini’s 802.16e system. Navini’s Ripwave products run in the unlicensed 2.4GHz ISM band, or the licensed 2.3 GHz WCS, 2.5/2.6 GHz ITFS/MMDS, and 3.4/3.5 GHz WLL bands.
MegaBroadband of Massachusetts launched the first commercial use of the 2.3GHz WCS spectrum in the U.S. using technology from Navini. They are partnering with BalRivgam, a WCS developer who is providing the spectrum. The initial network, located in Bristol County, Mass., will support up to 3,000 users. They plan to serve more than 10,000 users within 2 years.
SK Telecom and Korea Telecom (KT) have 2.3 GHz WiBro licenses thoughout South Korea and plan to launch it next year. They’ll be implementing Videocell Services next year and their mobilied version of WiMax (Wi-Bro). South Korea’s wireless broadband project is expected to cost $784 million to $900 million and provide ubiquitous broadband wireless throughout the country.
InfiNet Wireless selected the picoChip WiMAX solutions for its 802.16d and 802.16e WiMAX system designs. InfiNet, a leading vendor of Broadband Wireless Access equipment in Russia and Eastern Europe has supplied pre-WiMAX gear for more than 300 carrier-class wireless networks throughout the world.

System bandwidth (MHz) 1.25 2.5 5 10 20

* variable set only
** FFT size of 256 is not supported
Croatia has awarded 10 fixed line broadband wireless licenses for WiMAX in 3.5GHz, with WiMAX Telecom, one of the most progressive start-up operators in Europe, gaining a license for certain regions to add to its existing holdings in Austria and Slovakia.
Nortel Networks will build a commercial WiMax network in Alberta covering approximately 5 million acres in southeastern Alberta – using IEEE 802.16-2004 (pdf tutorial), the fixed WiMAX, standard. The WiMAX network will operate in the 3.5GHz spectrum band and be made available to roughly 80 percent of Alberta Special Areas Board residents by the end of summer 2006. It also will extend the service area of the Alberta SuperNet Project, a provincial government initiative that brings affordable broadband services to approximately 4,200 government, health, library and educational facilities in 429 communities across Alberta.

Data Rates Achieved at Various 802.16 Bandwidths

Airspan Networks and Yozan have expanded their contract to build a WiMAX network in Tokyo by $5 million, bringing the total contract size to $16.7 million (pdf). The project uses Airspan’s software-upgradeable radio technology using Airspan’s called MicroMAX-SDR, based on the PicoChip array. Airspan and Yozan announced plans to build a Tokyo-wide WiMAX network this March. It will enable mobilized voice, video, and broadband data services using Airspan’s software-upgradeable radio technology and will be upgraded to support 802.16e.
Intel said it expects to be involved with WiMax trials in Malaysia, Thailand and the Philippines by year-end. “The trials of the technology are starting now, and we see (commercial) roll-out worldwide over the next two to three years,” said Sean Maloney, the head of Intel’s mobility unit. “But it’s patchy — some places will be faster than others.”

NextNet Wireless, the supplier of gear for Clearwire, has NLOS Indoor, Outdoor and Mobile Subscriber Units (above). The mobile client (pdf) runs on 12 volts at 2300-2500, 2496-2690, 3300-3400, and 3400-3600 GHz. Clearwire plans to migrate to mobile WiMax, embedding it in a PCMCIA card by mid-2006, working with Intel.

TechDirt thinks it’s BS.

“Navini wins the award for the first to try to capitalize on this announcement by claiming they “lead” the mobile WiMax space. Navini, of course, wasn’t a WiMax supporter until last year when they switched camps, but they’re still offering their non-standard, proprietary wireless broadband and claiming it’s “pre-WiMax,” which somehow makes them a “leader.”

Navini says their Ripwave-MX dual-mode PCMCIA card, targeted for 1Q 2006, will both be software upgradeable to Navini’s 802.16e system. The card will be capable of switching between the current pre-WiMAX mode and 802.16e mode.

The Ripwave-MX Basestation, targeted for 1st half of 2006, will be software upgradeable to 802.16e and will continue to support the Smart Antenna functionality available from Navini today. Unwired Australia has 36,600 subscribers in Sydney while BellSouth has installations in the Gulf Coast and select Florida cities.
“WiMax was built for outdoor mobility,” said Paul Sergeant, director of marketing for WiMax at Motorola. “Wi-Fi wasn’t. The challenge we face going forward is getting WiMax into more devices; 2006 and 2007 will be the introduction and build-out years, and products will start shipping in volume in 2008 and 2009.”

Roger Marks, working group chairman, remarked in his announcement:

So, wherever on Earth you are, please join me in raising a glass
and sending out a virtual toast to the 802.16 family.
Konbe! Ganbei! Kampai!
L’Chaim! Belsalamati! Kippis! Skål! Sant !
Sl inte! Salute! Salud! Prost! Proost! Cheers!