Wireless video takes center stage
Once relegated solely to wired networks, enterprise video applications are becoming increasingly prevalent in the wireless arena and promise to be even more commonplace with recent improvements in virtually every aspect of the technology — from data rates to antennas to compression schemes. In fact, one vendor recently announced a compression scheme that — if legitimate — would turn the sector upside down.
The result of this activity has been an “unbelievable” proliferation of surveillance cameras during the last decade, said Mike Fergus, president of the Law Enforcement and Emergency Services Video Association.
“Between the traffic cameras and the private and publicly owned cameras, when you’re in a city, I wouldn’t be surprised if you’re captured a hundred times a day,” he said. “Ten years ago, you may not have been captured 10 times a day … and that was only in the biggest cities and in secure areas around banks.”
While many cameras are linked to a monitoring center via a high-speed fiber line, an increasing percentage are linked wirelessly for deployment in remote locations that lack wired backhaul or in developed areas with minimal disruption to existing infrastructure.
One solution is Motorola’s MotoMesh architecture, which was bolstered by the announcement that Motorola and Sony have developed a PCMCIA card that lets certain cameras act as a repeater/router in a mesh without any other hardware (see story on page 50).
For enterprises, getting video data to mobile workers can be as valuable as downloading video files at existing wireless data speeds can be frustrating. However, vendor giants Nortel Networks and Qualcomm recently announced that they completed the first high-speed data packet access mobile data calls in tests that achieved a transmission rate of 7.2 Mb/s over a single connection.
Such a data rate — as much as four times the speed of most fixed broadband connections — should allow a typical mobile user to realize a 200 kb/s to 1 Mb/s connection, depending on the service agreement and the load of the cell site, said a Nortel spokesman. That’s more than enough to view video on a mobile device, and the 7.2 Mb/s throughput theoretically could take wireless video to a new level, he said.
“If [the technology] was used over a dedicated link at that speed, you could use it to watch high-definition television,” he said.
To help carriers better address load capacity issues at a given cell site, TenXc Wireless recently announced the availability of its PCS Bi-Sector Array technology, which uses higher-order sectorization to let operators enhance capacity from existing towers. With this technology, an operator could double the capacity of a given antenna at a cost that is 80% less than the expense associated with adding another cell site, said Ross Ernst, TenXc’s vice president of marketing.
More important, these benefits can be deployed in a targeted manner, Ernst said. For example, in a typical three-sector site, there may be capacity issues in only one of the three sectors, so the TenXc solution could be deployed in the one troublesome sector without any re-engineering, he said (see graphic on page 8).
“The beauty is that they can make the investment right where the problem is,” Ernst said. “You’re addressing the problem right where it’s needed. With some other solutions, you need to upgrade a network, re-engineer a network or wait for handsets to absorb the feature … and operators almost need instant gratification.”
Although the PCS Bi-Sector Array is applicable for GSM, UMTS and CDMA operations in the 1.8 GHz to 2.2 GHz frequency range, Ernst said versions serving other frequencies would be available in the future.
Perhaps the most notable news foreshadowing the ubiquity of wireless video came from Euclid Discoveries, which announced that its EuclidVision object-based compression technology can achieve compression ratios of 15,168:1 for certain videos.
In tests, the company said it reduced a “streaming commentator” video file — one showing the head and shoulders of a subject — from 23 Mb to 1.519 Kb, which would allow video conferencing over virtually any network.
“The whole idea is to make video ubiquitous, so you don’t have to worry about what kind of network you’ve got,” said Richard Wingard, Euclid Discoveries CEO. “It’s going to put video conferencing on the map.”
Roger Entner, wireless telecom vice president at Ovum, expressed doubt about the claim.
“It sounds too good to be true — a 50% reduction would be awesome,” Entner said. “I’m extremely skeptical … I just don’t buy it.”
Wingard said the key is Euclid’s use of object-based compression, which isolates each object in a video and compresses it optimally. For this reason, EuclidVision handles full-motion video 460% better than MPEG-4 — and 600% better than MPEG-2 — without degrading the quality, he said. In fact, Wingard insists the company is being conservative with its claims that EuclidVision can compress a 700 Mb MPEG-4 file containing a two-hour movie to 50 Mb.
Currently, most videophones only provide about “two seconds of quality video” because video transmissions using existing compression schemes require too much bandwidth for mobile devices to function properly, Wingard said.
“We really solve that by reducing the transmission time and server space required for video without reducing the quality,” he said.
Quality is the primary concern for LEVA’s Fergus, who said the digital age has created problems for prosecutors trying to use surveillance footage as evidence. Compression schemes already produce distorted or unclear images that are not usable as evidence in court, and “ridiculously high” compression ratios like those claimed by Euclid could be a “nightmare” for law enforcement agencies trying to use the video, he said.
Public-safety entities should consider carefully the quality of video that is stored when making purchasing and operating decisions, Fergus said, noting that compressed video may look fine on a monitoring screen but may not provide the clarity necessary to withstand the rigors of court scrutiny.
“If all you’re interested in is getting enough video to fire an employee who’s stealing from you or if you just want to be able to measure the number of customers that stop and look at a display in a retail operation, then you don’t care what the quality is,” he said. “But, if you’re in a situation where you need to prosecute someone who is committing a crime, you need something a little bit better, and you need to think about it a little more closely.”
