Method and apparatus for routing data with support for changing mobility requirements

• US 7,346,015 B2
• Filed: 05/30/2002
• Issued: 03/18/2008
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: British Telecommunications PLC (BT Group PLC)
• Original Assignee: British Telecommunications PLC (BT Group PLC)
• Inventors: Shipman, Robert A
• Primary Examiner(s): Levitan; Dmitry
• Application Number:
  US10/480,143
• Publication Number:
  US 20040218528A1
• Time in Patent Office: 2,119 Days
• Field of Search: 370/468, 370/338, 370/312, 370229-237, 370/241, 370/242, 370248-250, 370/252, 370/253, 370/310, 370351-356, 370/389, 370/390
• US Class Current: 370/310
• CPC Class Codes: H04L 45/26 Route discovery packet
• CPC Class Codes: H04L 45/36 Backward learning
• CPC Class Codes: H04L 45/42 Centralised routing
• CPC Class Codes: H04W 40/22 using selective relaying for reaching a BTS [Base Transceiver Station] or an access point
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 40/248 Connectivity information update
• CPC Class Codes: H04W 40/30 for proactive routing

Abstract

A method of operating a wireless network with a base station and a plurality of outstations comprising

• • i. transmitting a broadcast signal from the base station;
  • ii. monitoring operational status of outstations in the wireless network from an outstation,
  • iii. collecting data representative of outstation status,
  • iv. in response to reception of the broadcast signal, transmitting an acknowledgement signal from the outstation;
    • wherein an outstation relaying an acknowledgement signal appends to the acknowledgement signal data representative of the collected data, and
    • wherein the base station, upon receipt of an acknowledgement signal, retrieves the collected data and varies the rate at which signals are broadcast from the base station in accordance with the collected data.

Claims

1. Apparatus for varying the rate at which signals are broadcast into a wireless network, wherein the signals are broadcast to facilitate route identification of a route along which data packets are subsequently passed, the apparatus comprising:

a. receiving means arranged to receive data representative of the status of at least one wireless device in the wireless network, and

b. modifying means arranged to modify the rate at which the signals are broadcast in accordance with the received data;

wherein the modifying means includes means operable to execute a sigmoid function in dependence on the received data, and provides as output a modified rate of issuing broadcast signals.

2. A method of identifying a route in a wireless network between a base station and a destination wireless device, the route comprising a sequence of wireless devices from the destination wireless device to the base station, the method comprising:

(i) from the base station, sending advertisement signals into the wireless network;

(ii) in response to receipt at the destination wireless device of one of the advertisement signals, generating an acknowledgement signal at the destination wireless device, the acknowledgement signal including an identifier representative of the destination wireless device;

(iii) transmitting the acknowledgement signal sequentially via each of the wireless devices of the sequence to the base station;

(iv) at each of the wireless devices of the sequence, modifying the acknowledgement signal received from the preceding wireless device by adding to the acknowledgement signal an identifier representative of the identity of the respective wireless device, and transmitting the modified signal, so that as the signal progresses along the sequence of wireless devices from the destination wireless device to the base station it acquires a sequence of identifiers representative of the identifiers of the wireless devices of the sequence, the sequence of identifiers representing a route between the base station and the destination wireless device; and

(v) at the base station, receiving the modified acknowledgement signal transmitted from the last wireless device of the sequence, and storing the route so obtained;

wherein a temporal interval between advertisement signals being sent into the wireless network from the base station varies based on a rate of changes in status, between active and inactive, of the wireless devices.

3. A method of identifying a route in a wireless network between a base station and a destination wireless device, the route comprising a sequence of wireless devices from the destination wireless device to the base station, the method comprising:

(i) from the base station, sending advertisement signals into the wireless network;

(ii) (in response to receipt at the destination wireless device of one of the advertisement signals, generating an acknowledgement signal at the destination wireless device, the acknowledgement signal including an identifier representative of the destination wireless device;

(iii) transmitting the acknowledgement signal sequentially via each of the wireless devices of the sequence to the base station;

(iv) at each of the wireless devices of the sequence, modifying the acknowledgement signal received from the preceding wireless device by adding to the acknowledgement signal an identifier representative of the identity of the respective wireless device, and transmitting the modified signal, so that as the signal progresses along the sequence of wireless devices from the destination wireless device to the base station it acquires a sequence of identifiers representative of the identifiers of the wireless devices of the sequence, the sequence of identifiers representing a route between the base station and the destination wireless device; and

(v) at the base station, receiving the modified acknowledgement signal transmitted from the last wireless device of the sequence, and storing the route so obtained;

wherein a temporal interval between advertisement signals being sent into the wireless network from the base station varies based on a rate of changes in status, between active and inactive, of the wireless devices; and

wherein the rate of changes in status of the wireless devices is determined based on the number of failures of wireless devices to connect to neighboring wireless devices.

4. A method of identifying a destination wireless device, for use in identifying a route, for subsequent transmission of date packets, between a base station and the destination wireless device, wherein the destination wireless device is in range of at least one other wireless device located within a wireless network, the wireless network comprising a base station operable to communicate with the wireless devices in the wireless network, the method comprising the steps of:

from the base station, sending advertisement signals into the wireless network;

receiving at the destination wireless device one of the advertisement signals;

generating an acknowledgement signal in response to receipt of the one of the advertisement signals at the destination wireless device, the acknowledgement signal including an identifier representative of the destination wireless device;

sending the acknowledgement signal from the destination wireless device to the base station via the at least one other wireless device;

wherein each of the at least one other wireless device modifies the acknowledgement signal by adding (i) an identifier representative of its identity and (ii) the number of failures to connect to neighboring wireless devices, before sending the acknowledgement signal on; and

wherein a temporal interval between advertisement signals being sent into the wireless network from the base station varies based on the number of failures.

5. A wireless network comprising:

a base station; and

a plurality of wireless devices; and

a destination wireless device;

wherein the base station broadcasts advertisement signals into the wireless network;

the destination wireless devices receives one of the advertisement signals and generates an acknowledgement signal in response to receipt of said one of the advertisement signals, wherein the acknowledgement signal including an identifier representative of its identity, and transmits the acknowledgement signal to the base station via each of the plurality of wireless devices in a sequence;

one of the plurality of wireless devices receives the acknowledgement signal, modifies the acknowledgement signal by adding an identifier representative of its identity, and transmits the modified acknowledgement signal to the base station via the sequence of wireless devices; and

the base station receives the modified acknowledgement signal transmitted from the sequence of wireless devices and stores the modified acknowledgement signal which includes a sequence of identifiers representative of the identifiers of the destination wireless device and the sequence of wireless devices, the sequence of identifiers representing a route between the base station and the destination wireless device for subsequent transmission of data packets;

wherein the rate at which the base station broadcasts advertisement signals into the wireless network varies based on the amount of activity of the network as determined by the wireless devices changing status between inactive and active.

6. A wireless network comprising:

a base station; and

a plurality of wireless devices; and

a destination wireless device;

wherein the base station broadcasts advertisement signals into the wireless network;

the destination wireless devices receives one of the advertisement signals and generates an acknowledgement signal in response to receipt of said one of the advertisement signals, wherein the acknowledgement signal including an identifier representative of its identity, and transmits the acknowledgement signal to the base station via each of the plurality of wireless devices in a sequence;

one of the plurality of wireless devices receives the acknowledgement signal, modifies the acknowledgement signal by adding an identifier representative of its identity, and transmits the modified acknowledgement signal to the base station via the sequence of wireless devices; and

the base station receives the modified acknowledgement signal transmitted from the sequence of wireless devices and stores the modified acknowledgement signal which includes a sequence of identifiers representative of the identifiers of the destination wireless device and the sequence of wireless devices, the sequence of identifiers representing a route between the base station and the destination wireless device for subsequent transmission of data packets;

wherein the rate at which the base station broadcasts advertisement signals into the wireless network varies based on the amount of activity of the network as determined by the wireless devices changing status between inactive and active; and

wherein the amount of activity is determined using the number of failures of wireless devices to connect to neighboring wireless devices.

7. The wireless network as in claim 6 wherein said one of the wireless devices further modifies the acknowledgement signal by adding its number of failures to connect to neighboring wireless devices before transmitting the acknowledgement signal to the base station.