Featured Research

from universities, journals, and other organizations

New Wireless Architecture Would Extend Cell-Phone Coverage To Where It Is Needed Most

Date:
June 12, 2001
Source:
University At Buffalo
Summary:
A new architecture for next-generation wireless systems for cellular phones proposed by University at Buffalo researchers could provide an efficient and flexible way to extend outdoor coverage, as well as provide indoor coverage, without building additional cellular phone towers. It also could make it much easier to complete a call on your cell phone, even when cell phone use is heaviest.

HELSINKI, Finland -- A new architecture for next-generation wireless systems for cellular phones proposed by University at Buffalo researchers could provide an efficient and flexible way to extend outdoor coverage, as well as provide indoor coverage, without building additional cellular phone towers. It also could make it much easier to complete a call on your cell phone, even when cell phone use is heaviest.

Called iCAR, (integrated Cellular Ad hoc Relay), the new system combines conventional cellular technology with Ad hoc Relay Station (ARS) technology, in which the stations relay or reroute calls from the congested cell to an adjacent one that is not congested.

An ARS is a wireless relaying device that receives a signal from a mobile handset or personal digital assistant and transmits it either to another ARS or to a regular cell tower. Unlike cellular towers, which have a range of a few kilometers, ad-hoc relay stations cover a much smaller area, typically only a few hundred meters.

An update on the new system was presented here today (June 12, 2001) at the 2001 IEEE International Conference on Communications. A paper on the system also will be published in an upcoming special issue of IEEE's Journal of Selected Areas of Communication (J-SAC).

The new system addresses what its developers say is the inability of the current cellular-phone system to effectively deal with "hot spots" that arise when demand for cellular phone calls in some areas surges, or when traffic becomes unbalanced among different cells.

That leads to the ironic situation with which most cell phone callers are all too familiar: Calls are most likely to be blocked or dropped under the precise circumstances in which people need to place them the most, such as on a convention floor inside an arena, or in an emergency, such as at a traffic accident or in a natural disaster.

According to the UB researchers, that situation arises because callers located in one "cell" cannot access resources available in neighboring cells.

"The shortcoming of these systems is that even though a neighboring tower may have channels available for use, if you are physically in a busy cell, you cannot place or receive calls," explained Chunming Qiao, Ph.D., UB associate professor of computer science and engineering. Qiao developed the system with Hongyi Wu, UB doctoral candidate in the Department of Computer Science and Engineering and Ozan Tonguz, Ph.D., UB professor of electrical engineering.

"The challenge is to find a cost-effective way to dynamically balance the traffic load among the cells," said Qiao. "With iCAR, this means finding a relay route consisting of Ad-Hoc Relay Stations that will lead from a congested cell to a non-congested cell."

The new system performed well in computer simulations conducted by the UB researchers.

Functionally, Qiao explained, the ARS is very similar to a cell tower, but on a much smaller scale. Cell phone towers have to be tall, he explained, because they need to cover a range of several kilometers. They are usually connected to a wired network using conventional copper or fiber-optic cables, and they must be built according to local zoning regulations with permission from authorities.

On the other hand, Qiao explained, because an ARS can have a far-more-limited range of, say, only several hundred meters, it can be small, perhaps as small as a cell phone, and since it is completely wireless, it also is portable. An ARS could be mounted on top of a vehicle or a building, or even be carried by an individual.

"Either technology by itself, the cell tower or the relay station, will not scale up cost-effectively," he said, "which is why integrating the two of them is such a good idea."

According to Qiao, the iCAR works well because it automatically will find a route, jumping from one ARS to another, until it finds an uncongested cell and it will do so in real time.

"If a route is available, it shouldn't take more than a few tens of milliseconds," said Qiao.

He added that the concept of using a completely separate channel for relaying -- for example, the unregulated 2.5 gigaherz frequency band -- also would apply to the integration of various wireless networks that are or will be available commercially, such as those based on HomeRF, Wireless LAN Bluetooth or even satellite networks.

The research is supported by the National Science Foundation's Information Technology Research program, and by the Nokia Research Center.


Story Source:

The above story is based on materials provided by University At Buffalo. Note: Materials may be edited for content and length.


Cite This Page:

University At Buffalo. "New Wireless Architecture Would Extend Cell-Phone Coverage To Where It Is Needed Most." ScienceDaily. ScienceDaily, 12 June 2001. <www.sciencedaily.com/releases/2001/06/010612065232.htm>.
University At Buffalo. (2001, June 12). New Wireless Architecture Would Extend Cell-Phone Coverage To Where It Is Needed Most. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2001/06/010612065232.htm
University At Buffalo. "New Wireless Architecture Would Extend Cell-Phone Coverage To Where It Is Needed Most." ScienceDaily. www.sciencedaily.com/releases/2001/06/010612065232.htm (accessed August 21, 2014).

Share This




More Matter & Energy News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com
Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Newsy (Aug. 19, 2014) Scientists have developed a new device that mimics the way octopuses blend in with their surroundings to hide from dangerous predators. Video provided by Newsy
Powered by NewsLook.com
Researcher Testing on-Field Concussion Scanners

Researcher Testing on-Field Concussion Scanners

AP (Aug. 19, 2014) Four Texas high school football programs are trying out an experimental system designed to diagnose concussions on the field. The technology is in response to growing concern over head trauma in America's most watched sport. (Aug. 19) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins