Wireless Network - Facts and Future Part 2 of 2
As a child starts to grow-up, one can get a glimpse as to what kind of adult they may be.
And so it is with wireless network technology. What has started off as a mere connection to a network shows signs of blossoming into a major communication infrastructure. Last month we discussed existing networks and some of the shortcomings. This month we will discuss new wireless technology that is under development and some ideas as to what wireless network technology will offer in the future.
The IEEE 802.15 Wireless Personal Area Network (WPAN) committee was established to design the wireless specifications for use as a personal network in the home or small business. As described in part 1 of this series, there are a couple of networks in service that meets this need. Consequent, the IEEE 802.15 committee has decided to use the structure and modulation of Bluetooth and Zigbee as a base for this standard. So we can expect the performance to be similar to that offered by Bluetooth and Zigbee.
The IEEE 802.16 WMAN committee was established to develop specifications for a wireless metropolitan area network. Initial considerations place the subject RF frequency above the 10 GHz spectrum. IEEE 802.16a is an extension to the original IEEE 802.16 charter. Its purpose is to make available a specification for a WMAN in the 5 GHz spectrum for High-speed Unlicensed Metropolitan Area Networks (HUMAN) with data rates reportedly to be superior to 802.11a specification.
802.20 W Mobile
The IEEE 802.20 W Mobile committee was established to develop specifications for a wireless mobile area network and initial considerations place the subject RF frequency bands below the 3.5 GHz spectrum. One of the main objectives will optimize IP data transport at peak rates of 1 Mb/s while supporting vehicular movement of 250 Km/h. The 802.20 specification fills the gap between high speed low mobility and high mobility cellular service. 
This committee was established to consider a Quality of Service (QoS) extension for the 802.11 wireless networks. QoS is an acronym describing the technology for high quality smooth display of audio and video streaming multimedia based on IEEE 1394 Firewire architecture (Firewire is the wired version of IEEE 1394 and should not be confused with the wireless version known as Bluetooth). Firewire IEEE1394a has wired transmission rates of 400 Mb/s and the IEEE 1394b has wired transmission rates of 1.6 Mb/s, both suitable for multimedia transmission. Collaborations between the IEEE 1394 and IEEE 802.11e are intended to incorporate QoS into the 802.11 specification. 
Cellular companies are very much interested in developing wireless network capability and 2G, 2.5G and 3G are the hot buzzwords in the cellular industry. Each of the cellular networks has varying implementations of the next generation cellular capability and all have plans to achieve wireless networking capability. Sprint plans to offer CDMA2000 high-speed wireless Internet access for laptop equipment with 802.11b. Reportedly, there are 800 hotpots nationwide that have been setup through an agreement with Airpath and Wayport. Verizon launched a similar CDMA2000 service providing Wi-Fi service through transmitters on its payphones. Likewise, AT&T plans to launch a GSM-based Wi-Fi service as well. Although all cellular wireless networks will perform at a much lower data transfer rate, their strength will be the ability to maintain a wireless network connection while the computing device is moving through the cellular network. 
Ultra-Wide Band (UWB) differs from all other Radio Frequency (RF) communications. An RF signal starts off as a pure sinusoidal waveform at a desired frequency. The wave is then modulated to carry data. With UWB data is digitally transmitted in an extremely short burst of no longer than a couple of picoseconds (trillionths of a second) in duration. The entire burst is complete before the RF waveform can complete one full cycle. The resultant is an extremely broadband transmission that is often difficult to determine the actual RF center frequency; thus the transmission is considered 'carrier free'. The pulse of data is so brief that it appears as background noise to other RF based communications working in the same frequency range. Studies have indicated that UWB may best operate in the 4.0 - 5.5GHz range. UWB products may be available in the 2005-2006 timeframe. UWB is suitable for short range of up to 10 meters where 802.11 defined range is up to 100 meters. Data rates of 500 MB/s are expected for WPAN devices like high capacity camera, PDAs, smart phones, home entertainment centers, printers, handheld computers, camcorders and MP3 players. 
Mesh networking stems from a battlefield awareness application funded by the Defense Advanced Research Projects Agency (DARPA). The concept of this project would be to drop several hundred sensors on a battlefield and each sensor could detect sound and communicate with nearby sensors and compare data and then transmit GPS data to a base station. The 'outstanding concept' is, there is not one controlling device and each device can relay information to another device until a device is found that is in contact with a base station. The application of Mesh Network to wireless networking is that any wireless network device could function as a relay station passing on data, thus extending the effective range of a wireless network.
TI has introduced a new chip called WANDA capable of connecting a single device to 802.11b, GSM cellular and Bluetooth wireless networks. Along that same line, HP intends to produce notebooks, tablet PCs and PDAs that would connect to 802.11 wireless networks and to cellular data networks. Another bridging device is the Buffalo Tech AirStation 54-Mb/s Wireless Compact Repeater Bridge-g. This device serves as an AP and bridge between 802.11a and 802.11b communications. Clearly, as this bridging technology develops having a computing device dedicated to just one wireless network may no longer be an issue.
In the future the line between PC and entertainment center will fade and it will be common for wireless tablets/PDAs to connect to the home entertainment center. One will be able to setup and play a sequence of songs or a movie from the convenience of one's couch or download the songs or a movie to their device to enjoy while on the move. Digital audio receivers are currently on the market and Sony RoomLink can wireless stream MPEG 1 & 2 video to their Sony Vaio TVs. Sony plans to release an 802.11a adapter later this year. Tablets/PDA will be plentiful and located throughout the home so one could conveniently access their e-mail, schedules, calendars or Internet. These devices would also be available to download the latest e-book, news stories of your specific interest or even monitor stock prices movements in real-time.
Tablets/PDA will become more common in the work place where presentation material could be displayed on the device during a presentation or conference. Checking conference schedules, personal schedules or calendar and e-mail while on the go will be effortless. But having to carry a table/PDA may not always be the case because electronics will continue miniaturization and will commonly be embedded into new areas.
Another type of wireless network under development by Microsoft Research is called Smart Personal Objects Technology (SPOT). This technology makes use of the unused frequency between existing radio stations and broadcast data, one way, to various types of devices. Currently, SPOT piggybacks a very low bandwidth data channel onto existing radio signals at 12 Kb/s. Some examples of this technology would be where an individual would open their closet in the morning to a panel that would display the weather forecast for the day as they were getting dressed. Another example would be where one could look at their watch on their way out the door to see a schedule of the day's meetings or events. Another would be as you started your car, a panel would display the current traffic conditions and suggest the best alternate routes. If you drive or fly to a different time zone, your watch would automatically update to local time. It could also display your personal calendar, contact information, local traffic reports, entertainment, news and stock reports. SPOT technology can be manufactured into almost anything like watches, key rings and refrigerator magnets, etc. 
Toys outfitted with radio gear will enable them to communicate with each other and to a wireless equipped media center. Dolls outfitted with a video camera could transmit video data to a TV so the child could see the world from the doll's point of view. Different doll personalities could be downloaded to the doll from the network. Toys could be equipped with GPS electronics so the child with toy could be tracked anywhere on the planet. There is a lot of interest in this area because some of these products have already started to appear on the market.
Wireless devices would be able to communicate with local shops when you are in the proximity of the shop. This would be convenient because when you walked by a shop or restaurant, you could see what the shop had to offer or see the restaurant menu and price before you entered. There is a project in California to construct a handful of billboards that detects the radio station that a passing motorist is listening to and then presents customized advertisements based on demographic data. We can expect to see similar technology evolve in the wireless tablet/PDA area.
Ultra High Band
The frequency region up to 5 GHz is essentially allocated. At frequencies above 20 GHz there are large amounts of unlicensed spectra available. There is over 1 GHz of space available in the 60 GHz range. Exponential improvements in CMOS technology should make accessible CMOS solutions in 10 years. As we reach for higher frequencies, one has to wonder where the X-ray and gamma ray bands start.
Wireless networks have a strong foothold and more individuals are starting to embrace this technology as it meets their needs. As more wireless specifications are ratified we can expect to see a blossom in the wireless development and deployment forever changing the communication landscape as we know it today. And like a child, the wireless network of the future may surprise us.
All 'Baby Steps to our Future' articles are archived at www.hal-pc.org/~seeker/future.
Ron Fenley worked as an engineer/analyst and retired in 1999. Ron moved to the country and now pursues his interest in computers, basic science and technology. Ron has been a computer enthusiast for 20 years and has been a HAL-PC member for about half that time. Ron can be reached at firstname.lastname@example.org