Ripping the cord
20 March 2009
Ultra-Wideband transmission: The perfect fit for wireless personal area networks. Jeff Chang reports.
Driven by innovations in mobility, power, and storage capacity, users continue to have a voracious appetite for the latest and greatest in consumer electronic gadgets. Add to that a new world of high definition content and social networking, and it’s no wonder that there is no end in sight to the potential growth of digital electronics. Wireless Personal Area Networks (or Wireless PANs) will play a key role in how people access, share and enjoy this content rich environment.
A Wireless PAN has a typical range of about 10 metres, and enables simple, secure connections to allow digital devices within range to communicate with one another. These connections may be mobile as in the scenario where a friend shares his latest digital photos with another friend via their handsets. Or they may be fixed as in a home office scenario where all of the peripherals (printer, speakers, monitor etc…) maintain a wireless connection with the PC.
Whatever the usage scenario, there is a need for a high-performance, low-power wireless solution that can achieve the price points to enable high volume applications such as handsets while also having the flexibility to meet all of the usage scenarios, and with minimal interference.
Herein lies the wireless divide. There have been proprietary technologies that have attempted to span the gap, but have ultimately failed. Standards-based technologies that are best suited for other applications have also attempted to make the leap, but with mixed results. One technology may be able to meet all of the stated requirements for high-performance Wireless PANs, and that technology is thought to be Ultra Wideband (UWB) transmission.
Bridging the divide (with a single-chip)
There are several reasons why UWB makes the perfect fit for Wireless PANs. First consider the requirements from the following user perspective:
Roberto purchases a new mobile phone that allows him to record a full hour of HD video as well as store his entire digital music collection (that’s 245 albums of Italian classical music and 1 country album). On Sunday, Roberto records his son’s soccer game with his new phone. For kicks, he also takes some pictures during half-time. A few of the other parents also want a copy of the pictures, so Roberto obliges by sharing them wirelessly. On his way back home, Roberto recharges his phone in the car, and upon arriving, downloads the pictures to his PC wirelessly and instantly, and then streams the video of the soccer game to his 60” HD flat panel TV. Also wirelessly, there is Italian classical music playing in the background on his 7.1 surround sound speaker system directly off his phone.
Based on this scenario, a user would require a wireless solution that is able to achieve high throughput (>100 Mbps) and low power (1-2 mW/Mbps), but also only at short range (<10 m). Users will not have the patience to wait for the files to transfer, as they have come to expect “instant gratification” with any new technology, nor will they want to charge their device multiple times throughout the day. They will also not tolerate disruption in their audio and video playback.
Take a Wireless LAN solution such as 802.11g, which is acknowledged to be a widely used and mature technology. At a maximum throughput of 20-25 Mbps and power consumption of 15-20 mW/Mbps, 802.11g falls well short of providing an optimal solution for Wireless PAN connections. In addition, 802.11 radios in a Wireless PAN setting have been shown to interfere with Bluetooth (thereby requiring current co-existence schemes), with Wi-Fi itself (causing disruption to the network/internet which is the primary usage model), as well as next generation IMT-2000 cellular services (WiMAX, LTE, UMTS). In addition, the 2.4 GHz ISM and 5 GHz UNII bands are becoming increasingly crowded with variants of Wi-Fi, Bluetooth, cordless phones, microwave ovens and other proprietary wireless solutions. Complex mitigation techniques could potentially be deployed, but there will be difficulty in addressing all of the user scenarios.
From a user perspective, 802.11 will provide slower connections, shorter battery life, and interruptions in service (e.g. loss of audio in wireless surround sound environment). And with a range of 50-100 m, the technology becomes pretty invasive for a Wireless PAN where a user wishes to only “see” connections within 5-10 m of their device.
In search of the killer app
We often fall into the trap of trying to identify that one killer app that will pull a technology over the divide. Looking back at history, someone had observed that killer apps are more “manslaughter”, as the driving application tends to occur after-the-fact. Although Bluetooth was defined for multiple use cases, ultimately it was the headsethandset connection that has made it ubiquitous. And take Wired USB, for example. The killer app was not a particular application per se, the killer app was actually bringing ease-of-use to PC connectivity. The next generation of Wired USB, Certified Wireless USB, merely takes this successful technology with end user familiarity, and removes the clutter of cables. It is more of an evolutionary step as opposed to a revolutionary one. New usage models are also introduced as described in the scenario above, and graphically shown in the figure left. Killer app or no, one critical attribute of all technologies that have successfully bridged the divide is cost. And perhaps cost can be considered the killer app in itself. If a technology is compelling, as UWB is for Wireless PAN, then at a certain cost point, integration “just happens”. It is up to the industry to provide the solutions that meet all of these requirements.
The Currency of UWB: single-chip CMOS
WiMedia UWB is a solution that can meet the strict requirements of high-performance Wireless PANs. In addition, UWB provides an interference-free and interruption-free environment with single-chip silicon.
In order to enable the multitude of usage models available for high-speed Wireless PANs, single-chip CMOS solutions must meet or exceed the requirements of high-volume applications, such as handsets, PC/PC peripherals, and consumer electronics. Looking yet again back at history, complementary wireless technologies such as Bluetooth and Wi-Fi have also followed a similar path in product integration. Low system cost, small size, low power and high performance are cornerstones of a successful technology, and only a single-chip CMOS implementation can achieve them all simultaneously. .
Mobility and portability are key trends in the handset, PC and consumer spaces, and only single-chip solutions can meet the stringent space requirements set forth by the OEMs..
JEFF CHANG is the Vice-President of Marketing at Staccato Communications
Contact Details and Archive...
Related Articles...
Most Viewed Articles...
