Resource management in uncoordinated frequency hopping system

• US 6,519,460 B1
• Filed: 08/30/1999
• Issued: 02/11/2003
• Est. Priority Date: 05/10/1999
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Haartsen, Jacobus Cornelis
• Primary Examiner(s): Le, Thanh Cong
• Assistant Examiner(s): Corsaro, Nick
• Application Number:
  US09/385,024
• Time in Patent Office: 1,261 Days
• Field of Search: 455/41, 455/452, 370/330, 370/480, 370/349, 375/131, 375/132, 375/133
• US Class Current: 455/452.1
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04B 7/2621 using frequency division multiple access [FDMA] H04B7/2615 takes precedence
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A method and apparatus are described for applying a narrow band FH link for low-rate and medium-rate communications, and a stationary wide band channel for high-speed (HS) communications. A master and one or more slaves sharing the same FH link may form a piconet. Master and slaves may hop synchronously according to a pseudo-random hop sequence. A master may control traffic on the FH link. An HS link can be established between a master and one or more slaves or between two slaves. An appropriate band of the radio spectrum is selected adaptively based on lowest RSSI measurements both in master and slave to establish the HS link without making use of a hopping scheme. A master shares its time between the HS slave on the HS link and the slaves remaining on the FH link using Time Division multiplexing. If the HS link uses a part of the band over which the piconet hops, the master controls the traffic such that the HS link is never visited by the FH link. If the HS link and the FH link do not overlap, then hop avoidance is not required. The HS slave-pair remains in contact with the master by a beacon signal used on the FH link. Periodically, HS slaves interrupt HS communications to listen the FH link. The beacon protocol includes slaves returning from the HS link to the piconet channel. In an alternative embodiment, slaves communication over HS link for a time interval. Slaves automatically return to FH link after the expiration of the time interval.

Claims

1. A method for communication using a plurality of time slots within a frequency spectrum, the method comprising the steps of:

establishing a frequency hopping traffic channel between a first and a second communication unit, the frequency hopping traffic channel having a set of the plurality of time slots and a set of hop carrier frequencies associated therewith;

establishing a stationary traffic channel between the first and the second communication unit, the stationary communication traffic channel having a location within the frequency spectrum associated therewith;

establishing the frequency hopping traffic channel between the first, the second, and a third communication unit; and

establishing the stationary traffic channel between the second and the third communication unit;

wherein the frequency hopping traffic channel avoids the location of the stationary traffic channel.

2. The method of claim 1, wherein the first communication unit is a master communication unit and the second and third communication units are slave communication units, and wherein the method further comprises the step of periodically transmitting a beacon packet from the master to one or more of the slave communication units over the frequency hopping traffic channel, the beacon packet indicating for the one or more of the slave communication units to release the stationary traffic channel and return to the frequency hopping traffic channel.

3. An apparatus for communication using a plurality of time slots within a frequency spectrum, the apparatus comprising:

a first communication unit coupled to a second communication unit;

wherein the first communication unit is configured to;

establish a frequency hopping traffic channel between the first and the second communication unit, the frequency hopping traffic channel having a set of the plurality of time slots associated therewith; and

establish a stationary traffic channel between the first and the second communication unit, the stationary communication traffic channel having a location within the frequency spectrum associated therewith,

wherein the first communication unit is further configured to;

establish the frequency hopping traffic channel between the first, the second, and a third communication unit; and

establish the stationary traffic channel between the second and the third communication unit;

and wherein the frequency hopping traffic channel avoids the location of the stationary traffic channel.

4. The apparatus of claim 3, wherein the first communication unit is a master communication unit and the second and third communication units are slave communication units, and wherein the first communication unit is further configured to transmit a beacon packet from the master to one or more of the slave communication units over the frequency hopping traffic channel, the beacon packet indicating for the one or more of the slave communication units to release the stationary traffic channel and return to the frequency hopping traffic channel.