Frequency hopping sequence allocation

Abstract

In a telecommunications system that employs frequency hopping techniques, network performance can be significantly improved by taking into consideration the level of interaction (e.g., the collision rate) between frequency hopping sequences, when allocating the frequency hopping sequences throughout the network. In a cellular network, this may be accomplished by deriving a network performance measure as a function of a current allocation of frequency hopping sequences for a number of cells and as a function of an expected collision rate (between the frequency hopping sequences) that appear for the current allocation. The frequency hopping sequences are then re-allocated amongst one or more cells until network performance is optimized. The allocation of frequency hopping sequences that results in optimized network performance may then be used for assigning frequency hopping sequences to new or existing connections (e.g., cellular calls) within a corresponding cell.

1 . A method for assigning a frequency hopping sequence to a mobile unit in a telecommunications network comprising the steps of: 
 allocating a plurality of frequency hopping sequences to a cell within the network as a function of a level of interaction between said plurality of frequency hopping sequences selected from a set of predefined frequency hopping sequences, wherein said level of interaction is a function of an intrinsic collision rate between pairs of said predefined frequency hopping sequences; and    selecting one of said plurality of allocated frequency hopping sequences for a connection associated with said mobile unit, in accordance with a frequency hopping sequence allocation strategy.    
   
   
       2 . The method of  claim 1 , wherein the frequency hopping sequence is a function of a hopping sequence number that has been assigned to the cell.  
   
   
       3 . The method of  claim 1 , wherein the frequency hopping sequence is a function of a corresponding frequency offset.  
   
   
       4 . The method of  claim 3 , wherein the frequency offset is a Mobile Allocation Index Offset value.  
   
   
       5 . The method of  claim 1 , wherein the frequency hopping sequence is a function of a frame number shift associated with the cell.  
   
   
       6 . The method of  claim 1 , wherein said step of selecting the allocated frequency hopping sequence for a connection associated with the cell, in accordance with a frequency hopping sequence allocation strategy, comprises the step of: 
 assigning the allocated frequency hopping sequence to the connection at set-up.    
   
   
       7 . The method of  claim 1 , wherein said step of selecting the allocated frequency hopping sequence for a connection associated with the cell, in accordance with a frequency hopping sequence allocation strategy, comprises the step of: 
 assigning the allocated frequency hopping sequence to the connection, wherein the connection is an existing connection.