Multirate wireless data communication system
DCFirst Claim
1. A method of operating a wireless local area network station adapted to transmit and receive messages at a plurality of data rates, wherein said messages include an initial portion and a data portion, including the steps of:
- transmitting the initial portion of a message to be transmitted by a station at a first predetermined data rate;
including in said initial portion at a data rate identification segment identifying a selected one of a plurality of data rates, at which said data portion is to be transmitted, and a length segment representing the length of time which would be required for a transmission of said data portion at one of said plurality of data rates; and
transmitting said data portion at said selected one of said plurality of data rates.
12 Assignments
Litigations
0 Petitions
Accused Products
Abstract
A wireless LAN includes first stations adapted to operate at a 1 or a 2 Mbps data rate and second stations adapted to operate at a 1,2,5 or 8 Mbps data rate. The 1 and 2 Mbps rates use DBPSK and DQPSK modulation, respectively. The 5 and 8 Mbps rates use PPM/DQPSK modulation. All four data rates use direct sequence spread spectrum (DSSS) coding. All transmitted messages start with a preamble and header at the 1 Mbps rate. The header includes fields identifying the data rate for the data portion of the message, and a length field. For a 2 Mbps transmission the length field identifies the number of bytes in the data field. For a 5 or 8 Mbps the length field identifies the number of bytes in the data field which, if transmitted at 2 Mbps, would take the same transmission time of the data field, and is thus a fraction 2/5 or 2/8 of the actual number of the bytes. With this arrangements, all the stations are interoperable in a co-existent manner in the LAN.
-
Citations
6 Claims
-
1. A method of operating a wireless local area network station adapted to transmit and receive messages at a plurality of data rates, wherein said messages include an initial portion and a data portion, including the steps of:
- transmitting the initial portion of a message to be transmitted by a station at a first predetermined data rate;
including in said initial portion at a data rate identification segment identifying a selected one of a plurality of data rates, at which said data portion is to be transmitted, and a length segment representing the length of time which would be required for a transmission of said data portion at one of said plurality of data rates; and
transmitting said data portion at said selected one of said plurality of data rates. - View Dependent Claims (2, 3, 4, 5, 6)
- transmitting the initial portion of a message to be transmitted by a station at a first predetermined data rate;
Specification