The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 06, 1998
Filed:
Oct. 04, 1996
Robert Lawrence Packer, Los Gatos, CA (US);
Milton Y Xu, San Jose, CA (US);
John Bettendorff, San Jose, CA (US);
Metricom, Inc., Los Gatos, CA (US);
Abstract
In a wireless frequency hopping communication system, a protocol, which does not employ carrier sense or collision detect, is provided for allocating bandwidth fairly and efficiently under varying load conditions, wherein a node is permitted random access to the medium bandwidth under light loading conditions and wherein under higher loading conditions a time/bandwidth allocation is made with a portion of the allocation dedicated to inband backhaul tasks by introducing a form of polling, the size of the reserved time/bandwidth allocation being selected based on traffic pattern. Under such heavy load conditions, non-slave traffic is allocated bandwidth in slots as pseudo-slave packets to guarantee a share of the bandwidth. Depending on the activity of the population of packets, including responsiveness and trend of responsiveness, the relative size of the slots is determined. Random access is always permitted for certain classes of packets, namely handshake packets, which are used to establish the master/slave relationships between nodes, no matter how a node is loaded. Once a master/slave relationship is established, a slave is only allowed to use the random access method to inform its master that it has data pending for transmission to the network when the node has a light load. Polling is always employed when the node at least has one active slave. According to one aspect of the invention, the size of the reserved allocation is based on a variable heartbeat of a multicast poll. Further in accordance with the invention, a handshaking between master and slave permits transition between operation in a random access mode and a polled mode.