Its promise is great, offering a wireless data-transmission technology for agencies with applications requiring high data rates. It can support voice over WLAN calls, large file transfers by multiple users, video streaming and conferencing applications.
Unfortunately we're in the "teaser" stage and actually putting it to use in an enterprise is years into the future.
Wireless in Root
Gi-Fi's evolution will likely follow the evolution of its cousin, Wi-Fi, which went from novelty to must-have. One limitation of Wi-Fi is its data transmission reach -- at approximately 150 feet, it's not good for much else besides the local coffeehouse or the average home.
For those craving long-range detachment, WiMAX, or broadband wireless access, is nearing commercial feasibility. Thanks to the Institute of Electrical and Electronics Engineers' (IEEE) ratification of the 802.16 standard in April 2002, WiMAX promises up to 10 miles of wireless access. It has been approved to operate in the 10 GHz to 66 GHz spectrum, but because the IEEE needs to address interoperability issues, the standard is still in progress.
WiMAX-certified products are expected to begin shipping in 2006 -- still some time off.
Gi-Fi Exposed
If WiMAX -- an extension of Wi-Fi's reach -- is still more than a year from full use, Gi-Fi is a glimmer in the eyes of wireless enthusiasts. Regardless of the time it might take Gi-Fi to gain wide use, its promoters argue Gi-Fi has a tangible purpose and could find a willing market.
Gi-Fi is intended strictly for the enterprise, said Paul Nikolich, chairman of the IEEE 802 LAN/MAN Standards Committee, adding that indoor applications running on Gi-Fi will operate at much higher data rates than standard Wi-Fi.
In 2003, the FCC cleared space in the 56 GHz band to offer high-speed use of applications that normally bog down slower networks, such as video. Dev Gupta, chairman of NewLans, presented a tutorial to the IEEE's LAN/MAN Standards Committee detailing the use of such speeds -- reaching 1 Gbps -- for enterprise applications.
According to the presentation, benefits of installing Gi-Fi include lower deployment and production costs, indoor/outdoor mobility, as well as availability and security comparable to wired networks.
Perhaps of all these issues, security is the most volatile.
With the proliferation of viruses, it is no surprise CIOs would be slow to transfer their departments' networks to wireless. Although wireless networks have proven their stability, some CIOs are leery of putting applications on the airwaves and sending data back and forth throughout a building with the threat of viruses riding those airwaves in.
There are two ways to look at the issue, Nikolich explained.
"Energy at 54 GHz experiences high attenuation as it passes through walls," he said. "This is good and bad: good because it will be difficult to eavesdrop through building walls, and bad because it will be difficult for signals to pass from room to room within a building where you may want to have communications."
Nikolich said electromagnetic waves that carry radio frequencies are attenuated -- or reduced in amplitude -- as they propagate away from the source.
"Think of dropping a pebble into a pond," he said. "The waves get smaller as they get farther from the point of impact. If the waves hit a barrier, like a wall, they get even smaller while some get reflected back toward the source."
Some energy carried by the electromagnetic waves will make it through the wall, he continued, but severely attenuated.
"In addition to the waves getting smaller as they get farther away, the rate at which they drop is a function of the medium they are propagating in," Nikolich explained. "So the waves would get smaller a lot faster if they were in a more viscous fluid, like a thick oil. The atmosphere behaves like a thick fluid at 54 GHz; this is why the attenuation is so high for those frequencies. At other, mainly lower, frequencies, the 'fluid characteristic' of the atmosphere becomes 'thinner.' The attenuation is less."
Networking Red Tape
Although the FCC opened up the band for such high-speed wireless connectivity, the IEEE has no current plans to ratify a Gi-Fi standard.
"The IEEE 802 LAN/MAN Standards Committee does not establish interest," Nikolich said. "Its members do. There simply were not enough members interested to begin a new work item in this area within the 802.11 Wireless LAN Working Group. However, there is a study group within the 802.15 Wireless PAN Working Group that is considering using the millimeter wave frequencies."
Industry reluctance has not prevented vendors like Extricom from developing products that will create an infrastructure platform for Gi-Fi to work from.
The company's architecture features the Extricom Switch and the Extricom Access Point (AP). According to Extricom, its WLAN architecture replaces the traditional concept of cellular-planned deployment with a continuous blanket of coverage encompassing the entire enterprise.
The other facet of the architecture is its APs, which according to the company, can be placed as close to one another as possible, to get high-quality, high-speed connectivity from all locations within the enterprise.
According to Tomer Geva, Extricom product manager, cell planning requires intensive radio frequency planning for each AP's coverage and interference footprints, as well as planning frequencies for each AP. But for this to work, the APs using the same frequency must be at least 500 feet apart.
"In typical large deployments, these requirements can rarely be met," said Geva. "This leads to co-channel interference between APs, resulting in dropped packets and retransmissions."
Another problem with traditional cell planning, Geva said, is the wait time that occurs when a user roams to a different AP's coverage area.
"In every handoff between APs, the user needs to change channels and reassociate to a different AP," Geva said. "This is a time-consuming process that can badly affect voice over WLAN user experience."
Extricom claims to overcome the problems inherent in cell planning with its architecture. According to Geva, the switch is connected to the network backbone and holds the "brains" of the system. This, combined with the APs connected to it, provides blanket coverage for users so they can access the network with limited downtime.
"Blanket coverage is full coverage of a WLAN deployment area by 'channel blankets,' a solution in which each AP throughout the deployment area is using the same channel," said Geva. "Extricom's architecture allows for multiple channel blankets, so an agency can multiply its network capacity by adding APs."
Wait and See Game
When equipment and software vendors are involved with government regulators who need to satisfy multiple connections, and standards boards who need to oversee its entire implementation, finding a cohesive manner in which to see the technology to fruition becomes an uphill battle at best.
Nevertheless, Gi-Fi is out there, and if the success of Wi-Fi and the imminent wide usage of WiMAX is any indication, Gi-Fi potentially can bring wireless broadband to the enterprise in an entirely new way.
