YOUR CART 0 items 
Hot Search:  th-f8 vhf  41-103-9R  bateria baofehg  case surecom  XwhS  DCsS  MKkZ  hf tunner  boefeng power switch  casesurecom  4-083y 4-079  icom ic- 7410  ct 118  kenwood round 8 pin  4-083y+4-079  
Code/Search:    Home  |   All Products  |   How to Buy  |   Payment Method  |   Post Tracking  |   My Address   |   Contact Us
  Hot News - How Ubiquitous Networking Will Work

How Ubiquitous Networking Will Work

Mobile computing devices have changed the way we look at computing. Laptops and personal digital assistants (PDAs) have unchained us from our desktop computers. A group of researchers at AT&T Laboratories Cambridge are preparing to put a new spin on mobile computing. In addition to taking the hardware with you, they are designing a ubiquitous networking system that allows your program applications to follow you wherever you go.


By using a small radio transmitter and a building full of special sensors, your desktop can be anywhere you are, not just at your workstation. At the press of a button, the computer closest to you in any room becomes your computer for as long as you need it. In addition to computers, the Cambridge researchers have designed the system to work for other devices, including phones and digital cameras.


As we move closer to intelligent computers, they may begin to follow our every move. In this edition of How Stuff WILL Work, we will look at the parts of such a system and how they allow our data and information to move with us.


In order for a computer program to track its user, researchers had to develop a system that could locate both people and devices. The AT&T researchers came up with the ultrasonic location system. This location tracking system has three basic parts:


Bats - small ultrasonic transmitters worn by users

Receivers - ultrasonic signal detectors embedded in ceiling

Central controller - coordinates the bats and receiver chains

Users within the system will wear a bat, a small device that transmits a 48-bit code to the receivers in the ceiling. Bats also have an imbedded transmitter which allows it to communicate with the central controller using a bidirectional 433-MHz radio link.


Bats are 3 inches long (7.5 cm) by 1.4 inches wide (3.5 cm) by .6 inches thick (1.5 cm), or about the size of a pager. These small devices are powered by a single 3.6-volt lithium thionyl chloride battery, which has a lifetime of six months. The devices also contain two buttons, two light-emitting diodes (LEDs) and a piezoelectric speaker, allowing them to be used as ubiquitous input and output devices, and a voltage monitor to check the battery status.


A bat will transmit an ultrasonic signal, which will be detected by receivers located in the ceiling approximately 4 feet (1.2 m) apart in a square grid. There are about 720 of these receivers in the 10,000-square-foot building (929 m2) at the AT&T Labs in Cambridge. An object’s location is found using trilateration, a position-finding technique that measures the objects distance in relation to three reference points.


If a bat needs to be located, the central controller sends the bat’s ID over a radio link to the bat. The bat will detect its ID and send out an ultrasonic pulse. The central controller measures the time it took for that pulse to reach the receiver. Since the speed of sound through air is known, the position of the bat is calculated by measuring the speed at which the ultrasonic pulse reached three other sensors. This system provides a location accuracy of 1.18 inches (3 cm) throughout the Cambridge building.


By finding the position of two or more bats, the system can determine the orientation of a bat. The central controller can also determine which way a person is facing by analyzing the pattern of receivers that detected the ultrasonic signal and the strength of the signal.



Search keyword does not accept symbols . , " ; .../ !   

  Antenna Parts


Accessory for Walkie-talkie
  SURECOM Product Line
  foot-earpiece foot-speaker-mMic foot-adaptor foot-power-supply
foot-repeater repeater cable foot-power-supply foot-dummy-load
SURECOM new Product line how-to-choose-earpiece   how-to-order-from-409shop
lexuma Shipping post  


Why Choose

    -Over 10,000 Radio products
    -Extremely low prices
    -Timely refunds and replacements
    -Worldwide free shipping (except F.O.B.)


Follow us on:

409shop-facebook 409shop-you-tube SKYPE-409shop 

Our Company

Learn & Support

Customer Service

Partner With Us


Software Downloads

PAY Method

Reseller Contact

About Us

Technical Support MAP

Post Tracking

Supplier Contact

My Company


Privacy Policy

Affiliate Program



Repair Return Address


Authority of AllSit Map

Tax Policy

Contact Us



   409shop Group: SURECOM | DAXSHINE | 409shop-TWO-WAY-RADIO | 409shop-moibleHKTDC | 對講機香港代 409shopradio 
   Quick buy: Buy Earpiece | Buy Speaker/Mic | Buy Antenna | Buy Adaptor | Buy UV5R 3800MAH battery | Buy SURECOM PRODUCT 
   Friendly Links 

walkie-talkie ,對講機牌照,DMR數碼對講機,cb對講機,motorola對講機香港 ,motorola數碼對講機,香港合法對講機,motorola對講機香港代理,motorola, t8對講機 ,motorola對講機耳機, 免費諮詢 , 409shop專業無線對講機生產 

google-site-verification: google6cffa68deb0f3230.html

Copyright © 2021 409shop,walkie-talkie,Handheld Transceiver All Rights Reserved.