Random access channel prioritization scheme

Abstract

The present invention relates to a method and to devices for transmitting and receiving data in a code division multiple access telecommunication system. A random access time window ( 20 ) is provided, which comprises a plurality of random access slots for transmitting random access data, for example from a mobile station ( 24 ) to a base station ( 25 ). The plurality of random access slots in the random access time window ( 20 ) is divided into at least two groups, whereby the groups are allocated to respective priority classes, whereby the priority classes represent the transmission priorities of the random access data to be transmitted in the random access slots. The present invention allows a reduction in congestion on the random access slots for certain access types at the expense of other access types and a more efficient use of the random access time window.

1. Method for transmitting and receiving data in a code division multiple access telecommunication system, comprising the steps of:
 providing a random access time window comprising a plurality of random access slots for transmitting random access data from at least one first communication device to a second communication device, and   dividing the plurality of random access slots of the random access time window into at least two groups each having a respective initial size, and   allocating the groups to respective priority classes,   whereby the priority classes represent the transmission priorities of the random access data to be transmitted in the random access slots,   whereby the size of at least one of said groups is changed in accordance with changing needs such that a probability of access for the at least one group is dynamically changed, and   whereby contents of one of said groups are permitted to overlap with another of said groups.   
     
     
       2. Method for transmitting and receiving data according to  claim 1 , characterized in,
 that the transmission priorities of the random access data to be transmitted are determined on the basis of the content and the type of the random access data.   
     
     
       3. Method for transmitting and receiving data according to  claim 1  characterized in,
 that the number of random access slots in each group is variably set depending on system requirements. 
 
     
     
       4. Method for transmitting and receiving data according to  claim 1 , characterized in,
 that a first communication device, for transmitting random access data of a certain transmission priority, randomly chooses one or more random access slots from the group having the corresponding priority class.   
     
     
       5. Method for transmitting and receiving data according to  claim 4 , characterized in,
 that the access probability depends on the number of random access slots in the group.   
     
     
       6. Method for transmitting and receiving data according to  claim 1 , characterized in,
 that said second communication device periodically broadcasts information defining the groups of the random access time window to the at least one first communication device.   
     
     
       7. Method for transmitting and receiving data according to  claim 1 , characterized in,
 that each random access slot in said random access time window is defined by a time offset value and a preamble code.   
     
     
       8. Device for transmitting and receiving data in a code division multiple access telecommunication system,
 in which a random access time window comprising a plurality of random access slots for transmitting random access data is provided,   the plurality of random access slots of the random access time window being divided into at least two groups each having a respective initial size, and   the groups being allocated to respective priority classes,   whereby the priority classes represent the transmission priorities of the random access data to be transmitted in the random access slots,   with means for randomly choosing one or more random access slots from a group having a certain priority class corresponding to the transmission priority of the random access data to be transmitted,   means for transmitting the random access data in said chosen random access slot(s),   whereby the size of at least one of said groups is changed in accordance with changing needs such that a probability of access for the at least one group is dynamically changed, and   whereby contents of one of said groups are permitted to overlap with another of said groups.   
     
     
       9. Device for transmitting and receiving data according to  claim 8 , characterized in,
 that the access probability depends on the number of random access slots in the group.   
     
     
       10. Device for transmitting and receiving data according to  claim 8 , characterized by,
 means for extracting information defining the groups of the random access time window from a received broadcast signal.   
     
     
       11. Device for transmitting and receiving data according to  claim 8 , characterized in,
 that each random access slot in said random access time window is defined by a time offset value and a preamble code.   
     
     
       12. Device for transmitting and receiving data in a code division multiple access telecommunication system,
 in which a random access time window comprising a plurality of random access slots for transmitting random access data is provided,   with means for dividing the plurality of random access slots of the random access time window into at least two groups each having a respective initial size,   whereby the groups are allocated to respective priority classes, the priority classes representing the transmission priorities of the random access data to be transmitted in the random access slots,   means for transmitting information defining the groups of the random access time window,   whereby the size of at least one of said groups is changed in accordance with changing needs such that a probability of access for the at least one group is dynamically changed, and   whereby contents of one of said groups are permitted to overlap with another of said groups.   
     
     
       13. Device for transmitting and receiving data according to  claim 12 , characterized in,
 that the transmission priorities of the random access data to be transmitted are determined on the basis of the content and the type of the random access data.   
     
     
       14. Device for transmitting and receiving data according to  claim 12 , characterized in,
 that said means for dividing the random access slots into groups sets the number of random access slots in each group variably depending on system requirements.   
     
     
       15. Device for transmitting and receiving data according to  claim 12 , characterized in,
 that each random access slot in said random access time window is defined by a time offset value and a preamble code.   
     
     
       16. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 randomly choosing one or more random access slots from a partitioned random access resource, and   transmitting the random access data by using the chosen one or more random access slots,   wherein the partitioned random access resource is established by partitioning available random access resources into a plurality of partitioned random access resources in accordance with a priority class which is assigned to the partitioned random access resource, wherein the partitioned random access resources is defined by at least one signature being assigned as one of available 16 separate signature codes corresponding to the available random access resources.   
     
     
       17. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 randomly choosing one or more random access slots from a partitioned random access resource, and   transmitting the random access data by using the chosen one or more random access slots,   wherein the partitioned random access resource is established by partitioning available random access resources into a plurality of partitioned random access resources in accordance with different priority classes being assigned to the plurality of partitioned random access resources, and   wherein the partitioned random access resource for transmitting the random access data is defined by at least one signature code which is assigned as one of available 16 separate signature codes and corresponds to a priority class assigned to the partitioned random access resource.   
     
     
       18. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 randomly choosing one or more random access slots from a partitioned random access resource, and   transmitting the random access data by using the chosen one or more random access slots,   wherein the partitioned random access resource is provided by partitioning available random access resources into a plurality of partitioned random access resources, each of the plurality of partitioned random access resources being defined by signature codes assigned from available 16 separate signature codes, in accordance with one or more priority classes being assigned to the plurality of partitioned random access resources.   
     
     
       19. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 randomly choosing one or more random access slots from a partitioned random access resource, and   transmitting the random access data by using the chosen one or more random access slots,   wherein the partitioned random access resource is provided by partitioning available random access resources into a plurality of partitioned random access resources to which different priority classes are assigned respectively, and   wherein the partitioned random access resource is defined by one or more signature codes, selected from available 16 separate signature codes, which correspond to the priority class assigned to the partitioned random access resource.   
     
     
       20. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 randomly choosing one or more random access slots from a divided random access resource, and   transmitting the random access data by using the chosen one or more random access slots,   wherein available random access resources are divided into a plurality of divided random access resources, the plurality of divided random access resources are defined by one or more signatures being selected from available 16 separate signature codes so that an access probability of the random access data in one divided random access resource is different from the access probability of the random access data in another divided random access resource of the plurality of divided random access resources.   
     
     
       21. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 randomly choosing one or more random access slots from a first random access resource, and   transmitting the random access data by using the chosen one or more random access slots,   wherein available random access resources are divided into at least a first random access resource and a second random access resource, the first and second random access resources being defined by first one or more signature codes and second one or more signature codes, respectively, which are assigned from available 16 separate signature codes to correspond to the available random access resources, and   wherein priority classes corresponding to transmission priority of the random access data to be transmitted are assigned to the random access resources so that an access probability of the random access data in the first random access resource is different from an access probability of the random access data in the second random access resource.   
     
     
       22. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 receiving information concerning the partitioning of random access resources provided by random access slots and 16 separate signature codes,   extracting information defining at least one group of random access resources assigned by access slots and signature codes,   defining transmission priority of a random access message, and   randomly choosing from the group of random access resources one or more random access resources defined by the random access slot and signature code that correspond to the transmission priority of the random access message in order to allocate the random access data to the one or more random access slots and signature codes.   
     
     
       23. The method of claim 22, characterized in that the transmission priority of the random access message is determined on the basis of an access class of a mobile station in the wireless communication system. 
     
     
       24. The method of claim 22, characterized in that the transmission priority of the random access message is determined on the basis of type of call in the wireless telecommunication system. 
     
     
       25. Method for transmitting random access data in a wireless telecommunication system, comprising the steps of;
 receiving information of partitioning of random access resources provided by random access slots and (16 separate) signature codes,   extracting information defining at least one group of random access resources assigned by access slots and signature codes,   defining content or type of random access message,   randomly choosing one or more random access resource defined by random access slot and separate signature code from the group of random access resources which correspond to the content or type of the random access message in order to allocate the random access data into the one or more random access slots and signature codes.    
     
     
       26. The method of claim 25, characterized in that the content or type of random access message is determined on the basis of call access or data transmission. 
     
     
       27. The method of claim 25, characterized in that the content and type of random access message is determined on the basis of call access or data transmission. 
     
     
       28. A wireless telecommunication system, comprising:
 means for randomly choosing one or more random access slots from a partitioned random access resource, and   means for transmitting the random access data by using the chosen one or more random access slots,   wherein the partitioned random access resource is established by partitioning available random access resources into a plurality of partitioned random access resources in accordance with a priority class which is assigned to the partitioned random access resource, wherein the partitioned random access resource is defined by at least one signature being assigned as one of available 16 separate signature codes corresponding to the available random access resources.   
     
     
       29. A wireless telecommunication system, comprising:
 means for randomly choosing one or more random access slots from a partitioned random access resource, and   means for transmitting the random access data by using the chosen one or more random access slots,   wherein the partitioned random access resource is established by partitioning available random access resources into a plurality of partitioned random access resources in accordance with different priority classes being assigned to the plurality of partitioned random access resources, and   wherein the partitioned random access resource for transmitting the random access data is defined by at least one signature code which is assigned as one of available 16 separate signature codes and corresponds to a priority class assigned to the partitioned random access resource.   
     
     
       30. A wireless telecommunication system, comprising:
 means for randomly choosing one or more random access slots from a partitioned random access resource, and   means for transmitting the random access data by using the chosen one or more random access slots,   wherein the partitioned random access resource is provided by partitioning available random access resources into a plurality of partitioned random access resources, each of the plurality of partitioned random access resources being defined by signature codes assigned from available 16 separate signature codes, in accordance with one or more priority classes being assigned to the plurality of partitioned random access resources.   
     
     
       31. A wireless telecommunication system, comprising:
 means for receiving information concerning the partitioning of random access resources provided by random access slots and 16 separate signature codes,   means for extracting information defining at least one group of random access resources assigned by access slots and signature codes,   means for defining transmission priority of a random access message, and   means for randomly choosing from the group of random access resources one or more random access resources defined by the random access slot and signature code that correspond to the transmission priority of the random access message in order to allocate the random access data to the one or more random access slots and signature codes.   
     
     
       32. A base station in a wireless telecommunication system, comprising:
 means for receiving random access data transmitted from a mobile station, and   means for generating an information signal necessary for operating the base station,   wherein the random access data was randomly provided in one or more random access slots from a partitioned random access resource at the mobile station,   wherein available random access resources are divided into at least a first random access resource and a second random access resource, the first and second random access resources being defined by first one or more signature codes and second one or more signature codes, respectively, which are assigned from available 16 separate signature codes to correspond to the available random access resources, and   wherein priority classes corresponding to transmission priority of the random access data that is transmitted are assigned to the random access resources so that an access probability of the random access data in the first random access resource is different from an access probability of the random access data in the second random access resource.