GB2390955A

GB2390955A - A broadband wireless coverage infrastructure

Info

Publication number: GB2390955A
Application number: GB0216691A
Authority: GB
Inventors: Stuart Philip Stenton; James Thomas Edward Mcdonnell; Matthew Murray Williamson
Original assignee: Hewlett Packard Co
Current assignee: HP Inc
Priority date: 2002-07-18
Filing date: 2002-07-18
Publication date: 2004-01-21
Also published as: GB0216691D0

Abstract

A system for providing broadband wireless coverage for a city street matrix, comprising wireless LAN base stations 1 situated on street junctions and having a directional antenna 2 providing an elongate footprint signal 3 aligned along a street. Provides the advantage over GPS systems and current third generation systems in that it eliminates blind spots in built up areas. Also enables more specific user location services as the user can be located down to a specific street. A broadband wireless coverage infrastructure wherein repeaters 6 are located at intersections in the city and which re-transmit signals to intersecting streets.

Description

À 2390955

BROADBAND WIFELESS COVERAGE INFRASTRUCTURE

This invention relates to broadband wireless coverage infrastructure and more particularly to broadband wireless coverage infrastructure optimised for a city street matrix.

The delivery of wireless coverage with the ability to offer street specific services throughout a city street matrix or similar metro/urban area is difficult to achieve especially at high bandwidths. At lower bandwidths, third generation (3G) cellular telecommunication network infrastructures can provide services but because of the size of a cell, it is difficult to make such services location specific. The combination of a third generation cellular telecommunication network with a global positioning system (GPS) is able to pinpoint accurately the location of a mobile unit within a cell to within say 1 metre or so but despite the accuracy of the location information, such a combination system still suffers from the drawbacks of the city skyline creating blind spots for the GPS and the 3G cellular telecommunication network coverage but also any service to be provided by such a combination would be at a 3G bandwidth which is, at most, ultimately intended to offer bandwidths in the order of 2Mbps.

Thus' there remains the problem of providing broadband wireless coverage offering street specific services within a city street matrix. It is an object of the present invention to seek to provide broadband wireless coverage overcoming the above-mentioned problems.

Accordingly, one aspect of the present invention provides a broadband wireless coverage infrastructure in a city street matrix, comprising a wireless LAN base PDNO 300200055-1

station having a directional antenna providing an elongate footprint signal aligned along a street within the city street matrix.

Preferably, a plurality of wireless LAN base stations are provided each having a directional antenna providing an elongate footprint signal.

Conveniently, a repeater is located at an intersection between two streets in the city street matnx, the repeater having a receiver, an amplifier and a transmitter and being operable to re-transmit a signal received from a wireless LAN base station positioned along a first sweet along another street intersecting the first street. Advantageously, the repeater has a directional transmit antenna providing an elongate footprint signal aligned along a street wit-hip the city matrix.

Preferably, the wireless LAN base station comprises a wireless LAN selected from the group consisting of: HiperLAN, 802.1 lb, 802.1 la, 802. 1 la, 802.1 le.

Conveniently, the wireless LAN base station is operable to provide location specific services to a mobile unit within range of Me wireless LAN base station.

Advantageously, the wireless LAN base station is operable to provide street specific services to a mobile unit within range of We wireless LAN base station.

Another aspect of the present invention provides a method of providing broadband wireless coverage in a city street matrix comprising the steps of: providing a wireless LAN base station having a directional antenna in a city street matnx, the directional antenna providing an elongate footprint signal; and PDNO 300200055-1

aligning the elongate footprint signal along a first street within the city street matrix. Preferably, a repeater is provided at an intersection between the first street and a second street intersecting the first street, the repeater having a directional transmit antenna providing an elongate footprint signal and the method comprises the further steps of: receiving at the repeater a signal from the wireless LAN base station, amplifying the signal from the wireless LAN base station; and hansmi the amplified signal from the transmit antenna, the directional transmit antenna having an elongate footprint signal aligned with the second street.

In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a schematic plan view of a city street matrix incorporating wireless coverage infrastructure embodying the present invention; Figure 2 is a schematic representation of a plea view of a thin elongate footprint signal produced by a directional antenna for use with embodiments of the present invention; and Figure 3 is a schematic representation of a plan view of a footprint signal produced by a conventional omnidirectional antenna.

Referring to Figure 1, many metropolitan and urban areas within city and town centres are laid out in a grid of buildings (B) separated from one another by roadways By) intersecting with one another at 90 . Clearly, not all areas within PDNO 300200055-1

a city will conform to such a strict grid arrangement and the example shown in Figure 1 is purely illustrative. Street intersections at angles of greater than or less than 90 and irregular spacings between roadways are often He case in practice. Notwithstanding the topology of the particular city street matrix, the common theme present in city street matrices are the thin elongate avenues of space between buildings and the intersections of those spaces - i.e. street corners. Attempting to install a wireless local area network (wLAN) such as one of the 802.11 family of specifications or HiperLAN in such an environment to provide

coverage over the matrix for mobile units on the street has heretobefore been difficult since the circular footprint of a wireless LAN would normally have a range in the region of 150 metros and that range would be curtailed by metallic structures within buildings and the terrain so preventing the footprint from a wireless LAN antenna frown reaching around corners and the like, commonly found in city street matrices.

To obviate this difficulty and derive more efficient coverage for a wireless LAN network in a city street matnx, referring to Figure 1, wireless LAN base stations 1 are connected to directional antennae 2 mounted, for example, over the road next to traffic lights or the like to provide pencil beam coverage along a street. The directional antennae 2 provide a Win elongate footprint 3 as shown in Figure 2, as opposed to the conventional footprint 4 shown in Figure 3.

Although having a more limited range than a cell based telecommunication network, the wireless LANs offer a much greater bandwidth (as much as 54Mbps) accessible along the length of a particular street depending upon me location of me base station 1 thereby enabling delivery of street specific PDNO 300200055-1

services through that wireless LAN base station 1 to a mobile device 5 equipped with a wireless LAN chip set. It can be appreciated that a user having a mobile device 5 and walking along a sheet will be within range of the wireless LAN base stations 1, along that street since the directional antennae 2 over the road will have their footprint 3 modified to conform substantially to the shape of the road - i.e. thin and elongate. Such directional antennae are readily available for wireless LAN operating frequencies, e.g. a Yagi high gain antenna. A preferred enhancement on the above described system utilises repeaters 6 mounted on the corners of buildings or at intersections to receive, amplify and redirect the signal from a wireless base station 1 through 90 along an intersecting road. Each repeater 6 consists of a receiver' an amplifier, a transmitter, an isolator and usually two antennae. There is frequency offset between the receiver and the transmitter so that the repeater receiver is not overwhelmed by the strong signal transmitted from the repeater transmitter.

The isolator serves to provide additional protection to prevent Me receiver being disabled. The antenna associated with the transmitter is also preferably directional again to direct the signal from the original wireless LAN base station 1 along a road intersecting the road upon which the original wireless LAN base station 1 is located, Hereby extending the range of the original wireless LAN base station 1 around city street corners (or more than one comer if many comer repeaters are provided).

The services offered by He wireless LAN base stations 1 can be customised to the sweet and He location within the city street matrix so that mobile units can be readily targeted by service providers located in the vicinity of that location.

Additionally, if the wireless LAN base stations are to allow access to other Bird party services, perhaps through a virlus1 private network connection to the POLO 300200055-1

Internet or remote servers, then the efficient footprints offered by the directional antennae 2 allow reliable connection through the wireless LANs to service providers which connection can be maintained at street level along roads without blind spots despite the urban environment Furler the broadband wireless coverage described above allows the possibility of efficient wireless LAN roaming as a mobile unit 5 passes from the sphere of influence of one wireless LAN base station into avowers hand over from one to the over being at good signal strength without blind spots.

In the present specification "comprises" means "includes or consists of' and

"comprising" means "including or consisting oft'.

The features disclosed in the foregoing description, or Me following claims, or

the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising Me invention in diverse forms thereof.

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Claims

1. A broadband wireless coverage inilastructure in a city street matrix, comprising a wireless LAN base station having a directional antenna providing an elongate footprint signal aligned along a street within the city street Manx.

2. A broadband wireless coverage inructure according to Claim 1,

wherein a plurality of wireless LAN base stations are provided each having a directional antenna providing an elongate footprint signal.

3. A broadband wireless coverage infrastructure according to Claim 1 or 2, wherein a repeater is located at an intersection between two streets in the cite street matrix, the repeater having a receiver, an Applier and a transmitter and being operable to re-transmit a signal received Dom a wireless LAN base station positioned along a first street along another street intersecting the first street.

4. A broadband wireless coverage infrastructure according to Claim 3, wherein the repeater has a directional transmit antenna providing an elongate footprint signal aligned along a street within the city matnx.

5. A broadband wireless coverage infrastructure according to any preceding claim wherein the wireless LAN base station comprises a wireless LAN selected from the group consisting of: HiperLAN, 802 11b, 802.11a, 802.1 la, 802.1 le.

PDNO 300200055-1

6. A broadband wireless coverage infrastructure according to any preceding claim, wherein the wireless LAN base station is operable to provide services specific to the location of the wireless LAN base station to a mobile unit within Me range of that wireless LAN base station.

7. A broadband wireless coverage infrastructure according to Claim 6, wherein the wireless LAN base station is operable to provide services specific to the street in which the wireless LAN base station is located.

8. A method of providing broadband wireless coverage in a city street matrix comprising the steps of: prodding a wireless LAN base station having a directional antenna in a city street matrix, We directional antenna providing an elongate footprint signal; aligning Me elongate footprint signal along a first street within the city street matrix

9. A method according to Claim 8, wherein a repeater is provided at an intersection between the first street and a second street intersecting the first street, the repeater having a directional transmit antenna providing an elongate footprint signal and the method comprises the furler steps of: receiving at the repeater a signal Tom the wireless LAN base station; amplifying the signal from the wireless LAN base station; and PDNO 300200055-1

transmitting Me amplified signal from the transmit antenna, We directional transmit antenna having an elongate footprint signal aligned wit e second street.

10. A broadband wireless coverage infrastructure substantially as hereinbefore described win reference to and as shown in the accompanying drawings.

11. A method of providing broadband wireless coverage substantially as hereinbefore described with reference to and as shown in he accompanying drawings. PDNO 300200055-1