Infrared backbone communication network having a radio frequency backup channel

• US 5,880,868 A
• Filed: 09/15/1997
• Issued: 03/09/1999
• Est. Priority Date: 03/29/1995
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Intermec IP Corporation (Honeywell International Inc.)
• Inventors: Mahany, Ronald L.
• Primary Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US08/929,593
• Time in Patent Office: 540 Days
• Field of Search: 359/143, 359/145, 359/146, 359/172, 359/152, 359/167, 455/73-74, 455/90, 370/310
• US Class Current: 398/115
• CPC Class Codes: H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
• CPC Class Codes: H04B 1/74 for increasing reliability, e.g. using redundant or spare channels or apparatus replacing by standby devices for amplifiers H03F1/52, H03F1/542
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information
• CPC Class Codes: H04B 10/40 Transceivers
• CPC Class Codes: H04L 12/403 with centralised control, e.g. polling
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 84/10 Small scale networks; Flat hierarchical networks
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication network which uses an infrared backbone and having a radio frequency backup channel is disclosed. The infrared backbone is generally located on a ceiling in a hallway of a building and comprises a plurality of hub access points. The hub access points communicate data on the backbone in a relay fashion using modulated infrared light. If infrared communications fail, the hub access points may, as a backup, communicate in the same fashion using low power radio frequency (RF) transmissions. Each of the hub access points also communicate with one or more non-backbone tap access points using infrared or RF transmissions. Tap access points are generally located on the ceiling in the hallway near an adjacent room and/or at some location in the adjacent room itself. A tap access point in the hallway is hard-wired through the ceiling to another tap access point or an antenna in the room, which permits communication with an end-point device in the room using infrared or RF transmissions. Again, RF may be used as a backup to infrared. The access points use a sequential polling protocol and relay data throughout the network. Absorptive triangular shaped panels are used to absorb and deflect infrared transmissions.

Claims

1. A communication network for use within a premises to maintain communication among a plurality of end-point devices, said network comprising:

a first tap access point device having an infrared transceiver and a radio frequency transceiver;

a second tap access point device having an infrared transceiver and a radio frequency transceiver;

a plurality of hub access point devices each having an infrared transceiver and a radio transceiver; and

each of the plurality of hub access point devices using the infrared transceivers when possible and, otherwise, the radio frequency transceivers to provide a communication pathway between the first and second tap access point devices.

2. The communication network of claim 1, wherein each of the plurality of hub access point devices use respective radio frequency transceivers when communication via respective infrared transceivers is unavailable.

3. The communication network of claim 1, wherein each of the plurality of hub access point devices use respective radio frequency transceivers when communication via respective infrared transceivers is unsuccessful.

4. The communication network of claim 1, wherein each of the plurality of hub access point devices attempt communication via respective infrared transceivers prior to employing respective radio frequency transceivers.