One would not call them intimate at this stage, but certainly the mutual interest between wireless local area networks (WLANs) and video applications is growing.
Companies and consumers already have deployed almost countless WLANs to support several kinds of data applications, such as electronic mail and Web browsing. But users are starting to dabble with video transmissions, which present a challenge because WLANs have lacked the bandwidth and the quality of service (QoS) functions to handle video-heavy traffic. Vendors have been trying to address these problems.
WLAN popularity has sprung up only during the last few years. Businesses like the flexibility WLANs offer employees. Consumers are enamored with the convenience WLANs deliver; they do not have to rip open the walls in their homes to move information from place to place.
As a result, market research firm Dell’Oro Group expects WLAN revenue to grow 20 percent in 2004 and reach US$2.1 billion worldwide. “Increasingly, users are showing more interest in video and voice systems and want to run these applications over their WLANs,” noted Allen Nogee, a principal analyst with market research firm In-Stat/MDR.
You Should Be in Pictures
A couple of factors are fueling the video interest. The variety of video input devices has been increasing. PC-based video conferencing systems enable companies to connect employees in various remote offices. Consumers are working with digital video recorders and media players that let them create multimedia content (music, photos and videos) on their PCs, stream it over wireless networks and display it on TVs or stereo systems. Not only are more video devices becoming available, but also pricing for these different products has been dropping.
As a result, new applications are emerging. Users can rely on wireless Web cameras to monitor children or nannies when the parents are out of the house. Video game consoles are becoming more realistic by featuring more video content, and wireless input devices provide users with more freedom.
Traditionally, wireless networks did not have enough bandwidth (802.11b networks operate at 11 Mbps) to support such applications. Recently, users have begun migrating to 802.11g wireless lans, which operate at 54 Mbps. “We have seen a shift recently, so the bulk of the networks being purchased support 802.11g,” Greg Collins, an industry analyst with market research firm Dell’Oro Group, told TechNewsWorld.
QoS features designed to ensure that bandwidth is available for specific applications, has been the biggest bugaboo for video transmissions. Because they are transmitting pictures and carrying sounds, video applications require a steady stream of bandwidth. Any little blip — and there are typically plenty on IP networks — distorts a picture or muddles a sound.
In response, the Institute of Electrical and Electronics Engineers forged the 802.11e task force to create a standard that will let network administrators establish priorities for different kinds of traffic (and give video highest priority and control of any unanticipated time delays) between WLAN transmissions.
These features, which are making their way into vendors’ products, make it more likely that a video application will have sufficient bandwidth to move information from sender to receiver without disruption.
ISDN No, WLAN Yes
As a result, corporations and consumers are beginning to use WLANs to support video transmissions. For example, the Concord, North Carolina, fire department has wanted to run video over its network for several years. “The city has a number of firefighter-training programs and employees have to come to a central location in order to watch them,” said Martin Belt, chief network engineer at Technologies Edge, an outsourcer that runs the city’s network.
He explained: “The city would have preferred that employees stay in their firehouses to watch the films, since that would enable them to respond to fires faster, but didn’t have a network capable of supporting the downloading of the films.”
Three years ago, the city considerred using ISDN lines to support the video application but found they were too expensive. Broadband options were not available in all locations, so the city turned to a WLAN system at the beginning of the year.
Currently, the fire department relies on Proxim WLAN adapters operating at 11 Mbps to connect 10 locations. Since making the change — which has gone smoothly — response time to local fires dropped from 5 minutes to 4 minutes, 30 seconds.
While video applications are becoming easier to deploy, they still present a few challenges to users. For one, they represent an additional expense: Users have to purchase video encoding devices and sometimes wireless receivers, which cost $100 to $200, to connect devices like televisions to wireless networks.
Getting the different components connected is usually more challenging than with WLANs, which are generally plug-and-play.
Many IP videoconferencing technologies rely on User Datagram Protocol — more commonly called simply UDP — to transmit between sites, but some firewalls sometimes block this traffic.
Network address translation — or NAT — lets multiple PCs access the Internet via one IP address, which also can cause problems. In certain cases, NAT lets video transmissions go out from the network but not come back in.
The end result is that analysts view the relationship between WLANs and video as an early courtship.
“Users have just begun trying to run video over WLANs, so a few unexpected problems have popped up,” In-Stat/MDR’s Nogee told TechNewsWorld. “I expect the problems to be ironed out in the next few years as more and more businesses and consumers deploy the technology,” he said.