Techniques for managing priority queues and escalation considerations in USB wireless communication systems

Abstract

Quality of Service (QoS) mechanisms and facilities are introduced into USB-based wireless Local Area Networking (LAN) communication systems. Techniques are provided for managing multiple priority queues in USB-based wireless communications systems, and for ensuring that lower priority traffic is not precluded from accessing the medium during sustained periods of use by high(er) priority traffic. A method is provided to resolve Quality of Service issues in emerging high-speed USB-based communications systems by offering support for multiple queue management within the system. A further embodiment provides an escalation mechanism for the purposes of mitigating low priority class data starvation in these communications systems, when it becomes an issue. QoS initiatives escalate a lower priority traffic class for the purposes of mitigating low priority class data starvation of the present invention, and/or use a single data buffer with management techniques to temporarily block or flow control data on a lower priority channel.

1 . A media access controller in a Universal. Serial Bus (USB) system, comprising: 
 a plurality of data queues having different priorities;    at least one escalation data queue;    a channel access interface; and    a queue manager to manage said plurality of data queues for service by said channel access interface;    wherein said queue manager places data from a lower priority one of said plurality of data queues into said at least one escalation data queue to alleviate a data starvation possibility to a lower priority one of said plurality of data queues.    
   
   
       2 . The media access controller in a Universal Serial Bus (USB) system according to  claim 1 , wherein: 
 said media access controller is integrated into a Universal Serial Bus (USB) device.    
   
   
       3 . The media access controller in a Universal Serial Bus (USB) system according to  claim 2 , wherein: 
 said USB device is a wireless device.    
   
   
       4 . The media access controller in a Universal Serial Bus (USB) system according to  claim 1 , wherein said plurality of data queues comprises: 
 at least two data queues.    
   
   
       5 . The media access controller in a Universal Serial Bus (USB) system according to  claim 1 , wherein said plurality of data queues comprises: 
 at least three data queues.    
   
   
       6 . The media access controller in a Universal Serial Bus (USB) system according to  claim 1 , further comprising: 
 a register adapted to block a USB packet for a certain endpoint as a function of a frame structure waiting in an incoming data queue.    
   
   
       7 . The media access controller in a Universal Serial Bus (USB) system according to  claim 6 , wherein: 
 said USB packet is blocked using a NAK/NYET mechanism.    
   
   
       8 . A method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation, comprising: 
 grouping a plurality of groups of data into respective classes for queuing and transmission; and    as quality of service rules require, escalating data of a lower priority to a highest class;    wherein lower priority class traffic is allowed to be transmitted periodically on a communication medium during sustained periods of high(er) class priority traffic transmission.    
   
   
       9 . The method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 8 , wherein: 
 said transmission is over a USB device.    
   
   
       10 . The method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 8 , wherein: 
 said USB device is a wireless USB device.    
   
   
       11 . The method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 8 , further comprising: 
 arbitrating between a pending transfer in a transmit state and a pending transfer in a receive state.    
   
   
       12 . The method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 11 , wherein said arbitrating comprises: 
 rotating between said transmit state and said receive state.    
   
   
       13 . The method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 8 , further comprising: 
 maintaining a request history buffer; and    blocking a subsequent request that is lower priority then a highest priority captured in said history buffer;    wherein an endpoint is blocked temporarily.    
   
   
       14 . The method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 8 , further comprising: 
 blocking a USB packet for a certain endpoint as a function of a frame structure waiting in an incoming data queue.    
   
   
       15 . The method for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 14 , further comprising: 
 releasing said USB packet as soon as at least one of said plurality of queues empties to an acceptable level.    
   
   
       16 . Apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation, comprising: 
 means for grouping a plurality of groups of data into respective classes for queuing and transmission; and    means for escalating data of a lower priority to a highest class as quality of service rules require;    wherein lower priority class traffic is allowed to be transmitted periodically on a communication medium during sustained periods of high(er) class priority traffic transmission.    
   
   
       17 . The apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 16 , wherein: 
 said transmission is over a USB device.    
   
   
       18 . The apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 16 , wherein: 
 said USB device is a wireless USB device.    
   
   
       19 . The apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 16 , further comprising: 
 means for arbitrating between a pending transfer in a transmit state and a pending transfer in a receive state.    
   
   
       20 . The apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 19 , wherein said arbitrating comprises: 
 means for rotating between said transmit state and said receive state.    
   
   
       21 . The apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 16 , further comprising: 
 means for maintaining a request history buffer; and    means for blocking a subsequent request that is lower priority then a highest priority captured in said history buffer;    wherein an endpoint is blocked temporarily.    
   
   
       22 . The apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 16 , further comprising: 
 means for blocking a USB packet for a certain endpoint as a function of a frame structure waiting in an incoming data queue.    
   
   
       23 . The apparatus for flow controlling a lower priority traffic class on a different Universal Serial Bus (USB) endpoint to mitigate low priority class data starvation according to  claim 22 , further comprising: 
 means for releasing said USB packet as soon as at least one of said plurality of queues empties to an acceptable level.