World Library  
Flag as Inappropriate
Email this Article

FLEX (protocol)

Article Id: WHEBN0001080186
Reproduction Date:

Title: FLEX (protocol)  
Author: World Heritage Encyclopedia
Language: English
Subject: Motorola, Radio paging, Motorola University, Motorola affair, Sanjay Jha
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

FLEX (protocol)

FLEX is a communications protocol developed by Motorola and used in many pagers. FLEX provides one-way communication only (from the provider to the pager device), but a related protocol called ReFLEX provides two-way messaging.

Transmission of message data occurs in one of four modes: 1600/2, 3200/2, 3200/4, or 6400/4. All modes use FSK modulation. At 1600/2 this is on a 2 level FSK signal transmitted at 1600 bits per second. At 3200/2, this is a 2 level FSK signal transmitted at 3200 bits per second. At 3200/4, this is a 4 level FSK signal transmitted at 1600 symbols per second. Each 4 level symbol represents two bits for a bit rate of 3200 bits per second. At 6400/4, this is a 4 level FSK signal transmitted at 3200 symbols per second or 6400 bits per second.

Data is transmitted in a set of 128 frames that takes 4 minutes to complete. Each frame contains a sync followed by 11 data blocks. The data blocks contain 256, 512 or 1024 bits for 1600, 3200 or 6400 bits per second respectively.

A BCH type ECC is used to improve the integrity of the data. The standard has been designed to allow the pager's receiver to be turned off for a high percentage of the time and therefore save on battery usage.

Security

Since data transmission over FLEX is unencrypted and insecure, transmitting private information over it should be done with caution. There have been reported instances of individuals actively listening to pager traffic (private investigators, news organizations, etc.).

In The Netherlands the emergency services use the Flex-protocol in the nationwide P2000 network for pagers. The traffic on this network can be monitored via several websites.

In South Australia the State's SAGRN network for the Emergency Services paging system (CFS, SES, MFS and SAAS) is run on the FLEX 1600 protocol, and can be monitored through several websites.

See also

External links

  • FLEX Technology: Paging Protocol
  • FLEX: The New Edge For The Paging Industry
  • Design And Implementation Of A Practical FLEX Paging Decoder
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.