Browse Prior Art Database

GUARANTEED MECHANISM FOR MESSAGE RETRANSMISSION

IP.com Disclosure Number: IPCOM000008924D
Original Publication Date: 1999-Jan-01
Included in the Prior Art Database: 2002-Jul-24
Document File: 3 page(s) / 138K

Publishing Venue

Motorola

Related People

Anupam Koul: AUTHOR [+2]

Abstract

On a typical paging terminal users can retrieve pages sent to them using the message retransmission feature. The user inputs the sequence number(s) of the messages that he/she desires to be retransmitted to his pager. The user input could be a single sequence number or a range of sequence numbers. This input is communicated by the telephone han- dling subsystem to the central processing subsystem of the paging terminal. A serial communication pro- tocol may be followed between these two subsys- tems. The lower message sequence number, upper message sequence number and the number of mes- sages in the tank are communicated by the central processor to the telephone handling subsystem for the user input to be validated and messages to be retransmitted successfully. The tank referred to here is typically a storage allocated to each subscriber in the central processing subsystem for storing mes- sages.

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MO-LA Technical Developments

GUARANTEED MECHANISM FOR MESSAGE RETRANSMISSION

by Anupam Koul and Kumar Kalluri

  On a typical paging terminal users can retrieve pages sent to them using the message retransmission feature. The user inputs the sequence number(s) of the messages that he/she desires to be retransmitted to his pager. The user input could be a single sequence number or a range of sequence numbers. This input is communicated by the telephone han- dling subsystem to the central processing subsystem of the paging terminal. A serial communication pro- tocol may be followed between these two subsys- tems. The lower message sequence number, upper message sequence number and the number of mes- sages in the tank are communicated by the central processor to the telephone handling subsystem for the user input to be validated and messages to be retransmitted successfully. The tank referred to here is typically a storage allocated to each subscriber in the central processing subsystem for storing mes- sages.

  Most paging terminals out there in the market today allow a user to input a max. of two digits for the message sequence that he/she desires to be retransmitted. These digits denote a single chosen sequence number, or denote a fixed number of most recent messages to be resent. In the case of a user entering a valid range of sequence number (user inputs four digits), the protocol information inter- changed is not enough to successfully retransmit all possible permutations and combinations of this user input. Instances of this anomaly are pronounced spe- cially when the message sequence number rolls over. Further problems arise when the maximum message sequence number and the tank size are unequal and varying (configurable).

  An example of the user input sequence range failing the validation test, thereby not being able to retransmit the messages is given in the next column.

  Let us assume the message storage tank to be able to accommodate 10 messages at any given time per subscriber. Let us consider the tank to contain the following messages (denoted by the sequence numbers):

14, 15, 16, 17, 18, 19,20, 1,2,3 In this case, the protocol conveys the following information:

Lower Message Sequence No. = 14 Upper Message Sequence No. = 3 Number of Messages in the tank = IO A valid user input should conform to the follow- ing rules:

14<=s<=3 14c=E<=3 S<=E where

L = Low Seq. No. From Msg. Tank U = Upper Seq. No. From Msg. Tank S = User Input Start Message Seq. No E = User Input End Message Seq. No

  With this kind of a setup, there are bound to be cases where the user input shall be incorrectly vali- dated, thereby making the message retransmission attempt unsuccessful. For example, a valid user input sequence range such as 20-01 would success- fully retransmit messages. Ho...