WO2011101655A1

WO2011101655A1 - Wireless communication system with wireless backhaul connection

Info

Publication number: WO2011101655A1
Application number: PCT/GB2011/050256
Authority: WO
Inventors: Piers Glydon; Andrew John Fox
Original assignee: Deltenna Limited
Priority date: 2010-02-22
Filing date: 2011-02-11
Publication date: 2011-08-25
Also published as: GB2477979B; GB201002947D0; GB2477979A

Abstract

An access point has a first access interface, adapted to allow access from at least one user device; radio frequency transceiver circuitry for communicating over a wireless link with a base station selected from a plurality of available base stations; an antenna system, having a plurality of available beam directions; and control circuitry, for determining data rates available over wireless links with said plurality of available base stations. The access point is configured to: repeatedly determine a preferred one of said available beam directions, based on available data rates at different times; and at a particular time of use, select a beam direction for use, based on the particular time, wherein the selected beam direction is the preferred one of said available beam directions at a time corresponding to the particular time. This allows the access point to establish connections with different base stations at different times of the day or week, taking advantage of the varying loadings on the base stations in order to obtain a higher data throughput.

Description

WIRELESS COMMUNICATION SYSTEM

WITH WIRELESS BACKHAUL CONNECTION

This invention relates to a wireless communication system, and in particular to a wireless communication system including an access point, having a wireless backhaul connection.

WO2008/068495 discloses a wireless access point, which allows users of personal computers or other similar devices to establish a wireless connection with the access point. The access point then has a wireless connection into a cellular communications network, for example allowing the users of the personal computers to access the internet. The wireless access point has a controllable antenna beam direction, and suitable control of this beam direction can allow the wireless access point to establish a connection with a selected base station of the cellular communications network.

Specifically, the data rate that is achievable can be measured for various antenna beam directions. The wireless access point can then be operated using the beam direction that gives the highest data rate.

According to a first aspect of the present invention, there is provided a method of operating an access point, wherein the access point is adapted to allow access from at least one user device, wherein the access point comprises radio frequency transceiver circuitry for communicating over a wireless link with a base station selected from a plurality of available base stations, and wherein the access point has a plurality of possible antenna beam directions; the method comprising: repeatedly determining a preferred one of said available beam directions, based on available data rates at different times; and at a particular time of use, selecting a beam direction for use, based on the particular time, wherein the selected beam direction is the preferred one of said available beam directions at a time corresponding to the particular time. According to a second aspect of the present invention, there is provided an access point, comprising: a first access interface, adapted to allow access from at least one user device; radio frequency transceiver circuitry for communicating over a wireless link with a base station selected from a plurality of available base stations; an antenna system, having a plurality of available beam directions; and control circuitry, for determining data rates available over wireless links with said plurality of available base stations, wherein the access point is configured to: repeatedly determine a preferred one of said available beam directions, based on available data rates at different times; and at a particular time of use, select a beam direction for use, based on the particular time, wherein the selected beam direction is the preferred one of said available beam directions at a time corresponding to the particular time.

This has the advantage that the access point can take account of regularly occurring changes in the data throughput that is available from different base stations. For a better understanding of the present invention, and to show how it can be put into effect, reference will now be made, by way of example, to the accompanying drawings, in which:-

Figure 1 is a block schematic diagram, illustrating a first wireless communication system in accordance with an aspect of the invention.

Figure 2 is a more detailed block schematic diagram of an access point in the system of Figure 1 . Figure 3 is a more detailed block schematic diagram of a part of the access point of Figure 2.

Figure 4 is a block schematic diagram, illustrating a second communication system in accordance with an aspect of the invention.

Figure 5 is a more detailed block schematic diagram of an access point in the system of Figure 4.

Figure 6 is a flow chart, illustrating a method of operation of the access point of Figure 2 or Figure 5, in accordance with a further aspect of the invention.

Figure 7 is a flow chart, illustrating in more detail a part of the method of Figure 6.

Figure 8 is a flow chart, illustrating a method of operation of the access point of Figure 2 or Figure 5, in accordance with a further aspect of the invention. Figure 1 shows a wireless communications environment 10, containing a wireless access point 12. The wireless access point 12 provides wireless access for a user of a suitably equipped mobile communications device 14, which may for example be a laptop computer, or another portable device. The wireless access point 12 can for example operate in accordance with one of the family of IEEE 802.1 1 standards, for example the standards commonly known as WiFi or WiMax. Alternatively, the wireless access point 12 can for example be a GSM pico base station, or any other base station or access point providing local area wireless coverage. For this purpose, the wireless access point 12 includes a first antenna 16, which may for example be an

omnidirectional antenna.

The user of the mobile communications device 14, and other suitably equipped devices within the coverage area of the access point 12, can then transfer data to and from the access point 12. In order for the user of the mobile communications device 14 to be able to communicate with other users, or to be able to download data, for example from websites, the access point 12 needs to have a connection over a suitable network.

In the example shown in Figure 1 , the wireless access point 12 is located in a wireless communications environment 10, which is typical of many urban areas, in that the wireless access point 12 is located in the coverage areas of a number of cellular base stations, in this case a first base station (BS1 ) 18, a second base station (BS2) 20 and a third base station (BS3) 22. As is well known, each of these cellular base stations 18, 20, 22 has a connection into the Public Switched Telephone Network (PSTN) (not shown), or into a packet data network, allowing it to establish voice and data calls to and from users of mobile phones and other suitably equipped mobile communications devices within their respective coverage areas.

In accordance with the invention, the access point 12 is provided with a suitable antenna 24, and radio frequency communications circuitry (not shown in Figure 1 ), allowing it to establish a connection with some or all of the cellular base stations 18, 20, 22. By establishing a connection with one of the cellular base stations, the access point 12 is able to transfer data between the user 14 and a location accessible over the PSTN. For example, the access point can establish a connection between the user 14 and a website to allow the user 14 to download content from the website. Thus, the access point 12 uses the respective cellular network to provide backhaul for its data. As another illustrative example, the user device may be a VoIP (Voice over IP [Internet Protocol]) phone, establishing an IP connection through the access point 12, with backhaul over the cellular network, to another VoIP phone having an internet connection.

Figure 2 is a schematic diagram, illustrating in more detail the form of the access point 12. As mentioned previously, the access point 12 has a first antenna 16, for communication with users of suitably equipped mobile communications devices, in accordance with one of the family of IEEE 802.1 1 standards, and the antenna 16, may for example be an omnidirectional antenna to allow communication with suitably equipped mobile communications devices in the whole area around the access point 12.

The antenna 16 is connected to local area coverage RF circuitry 26, as would conventionally be found in an access point operating in accordance with that standard. For example, where the access point 12 operates in accordance with one of the family of IEEE 802.1 1 standards, the local area coverage RF circuitry 26 is able to convert received signals into the appropriate data stream, and is able to convert incoming data into signals suitable for transmission over the wireless interface in accordance with that standard.

The local area coverage RF circuitry 26 is connected to cellular coverage RF circuitry 28, as would conventionally be found in a mobile communications device suitable for operating in accordance with the relevant standard or standards. For example, where the access point 12 is intended to establish a connection with a cellular base station (for example, one of the base stations 18, 20, 22) operating in accordance with the GSM standard, then the cellular coverage RF circuitry 28 includes appropriate GSM circuitry. Similarly, where the access point 12 is also intended to establish a connection with a cellular base station (for example, one of the base stations 18, 20, 22) operating in accordance with the UMTS standard, then the cellular coverage RF circuitry 28 also includes appropriate UMTS circuitry.

In this illustrated embodiment of the invention, the cellular coverage RF circuitry 28 is connected to power control circuitry 30, as will be described in more detail below. The power control circuitry 30 is connected to antenna direction control circuitry 32, which in turn is connected to the cellular antenna 24.

The cellular coverage RF circuitry 28, the power control circuitry 30, and the antenna direction control circuitry 32 operate under the control of a controller 34.

The access point 12 receives electrical power from a power source 36. The power source 36 may be a mains electrical power source, or an electrochemical battery, or may be a power source deriving energy from its environment, such as a solar power source, or a wind power source, or combined wind/solar power source.

The access point 12 operates under the control of a management system 38. The management system 38 is typically contained in firmware running on a processor inside the access point, and can control the operation of the access point 12. It can alternatively be provided on a remote computer. For example, the management system 38 can be connected to the access point 12 over an existing local area network (LAN), or may be wirelessly connected to the access point 12, for example allowing the remote management system 38 to configure the link via ftp, or via a website provided for that purpose. The management system 38 can then, for example, control the security of the access point, determining which user devices are permitted to establish connections thereto.

Figure 3 is a more detailed block schematic diagram of a part of the access point 12. Specifically, Figure 3 shows in more detail the cellular coverage RF circuitry 28, the power control circuitry 30, the antenna direction control circuitry 32, and the cellular antenna 24.

As shown in Figure 3, the antenna 24 includes four antenna elements 24a, 24b, 24c, 24d, although it will be appreciated that any convenient number of antenna elements can be provided. In particular, an antenna with eight antenna elements may be particularly suitable for this implementation. Each of these antenna elements 24a, 24b, 24c, 24d is directional. That is, each of the antenna elements 24a, 24b, 24c, 24d transmits signals preferentially in one direction, in azimuth, and is most sensitive to received signals from the same direction. These preferential directions are preferably all different, and are equally spaced around the azimuth, such that the antenna 24 is essentially omnidirectional. However, it is also possible for the antenna 24 to be formed of antenna elements whose preferential directions are not equally spaced in this way, with the result that the antenna 24 will not be omnidirectional, but will be at least somewhat directional. As mentioned above, the cellular coverage RF circuitry 28 is connected to power control circuitry 30, which is shown in more detail in Figure 3. For example, the power control circuitry 30 could include a duplexer 42, for separating and combining signals at the RF transmit and receive frequencies in the relevant cellular networks. Thus, transmit signals from the cellular coverage RF circuitry 28 pass through the duplexer 42 to a power amplifier 44, before being passed to the antenna direction control circuitry 32. The power amplifier is provided in order to be able to amplify the signals more than would usually be the case in a cellular user equipment, thereby allowing the access point to establish a connection to a cellular base station (for example one of the base stations 18, 20, 22, shown in Figure 1 ) that is more distant than the base station that a cellular base station would conventionally access. The degree of amplification provided by the power amplifier 44 is determined by the controller 34 by means of a signal passed along a control line 46. Somewhat similarly, received signals from the antenna 24 and the antenna direction control circuitry 32 pass through a low noise amplifier 48, before being passed through the duplexer 42 to the cellular coverage RF circuitry 28. The low noise amplifier 48 is provided in order to be able to amplify the signals more than would usually be the case in a cellular user equipment, thereby allowing the access point to establish a connection to a cellular base station (for example one of the base stations 18, 20, 22, shown in Figure 1 ) that is more distant than the base station that a cellular base station would conventionally access. The degree of amplification provided by the low noise amplifier 48 is determined by the controller 34 by means of a signal passed along a control line 50.

After passing through the power amplifier 44, the transmit signals are divided, and passed through respective gain control elements, in this case controllable attenuators 52a, 52b, 52c, 52d, and through respective duplexers 54a, 54b, 54c, 54d to the respective antenna elements 24a, 24b, 24c, 24d. Somewhat similarly, received signals from the antenna elements 24a, 24b, 24c, 24d pass through the respective duplexers 54a, 54b, 54c, 54d to respective gain control elements, in this case controllable attenuators 56a, 56b, 56c, 56d, before being combined and passed to the low noise amplifier 48.

The degree of attenuation provided by each of the controllable attenuators 52a, 52b, 52c, 52d, and 56a, 56b, 56c, 56d is determined by the controller 34 by means of signals passed along a control line, or lines, 58. Thus, by controlling the degree of attenuation in each of the signal paths to and from the antenna elements 24a, 24b, 24c, 24d, the effective beam shape of the antenna 24 can be altered. That is, if each of the controllable attenuators 52a, 52b, 52c, 52d, and 56a, 56b, 56c, 56d provides an equal degree of attenuation, or provides no attenuation at all, the antenna elements 24a, 24b, 24c, 24d transmit signals with equal amplitudes, and are equally sensitive to received signals, and so, depending on the respective preferred directions of the antenna elements 24a, 24b, 24c, 24d, the antenna 24 may be effectively omnidirectional.

By contrast, if the signals in the signal paths to and from one of the antenna elements 24a, 24b, 24c, 24d are not attenuated, or are only slightly attenuated, while the signals in the signal paths to and from the other antenna elements 24a, 24b, 24c, 24d are strongly attenuated, the effective beam shape of the antenna 24 strongly resembles the beam shape provided by the antenna element whose signals are not attenuated, or are only slightly attenuated.

That is, by suitable control of the controllable attenuators 52a, 52b, 52c, 52d, and 56a, 56b, 56c, 56d the antenna 24 can be made to be highly directional.

Usually, the controllable attenuators 52a, 52b, 52c, 52d, and 56a, 56b, 56c, 56d are controlled such that the attenuators of the pairs 52a, 56a; 52b, 56b; 52c, 56c; and 52d, 56d in the signal paths to and from the respective antenna elements 24a, 24b, 24c, 24d are controlled in the same way, such that the antenna 24 has the same beam shape and size in the uplink path as in the downlink path, but this need not necessarily be the case. Although the invention is illustrated above with reference to an embodiment in which controllable attenuators are located in the signal paths to and from the antenna elements, it is equally possible to provide a beam switched antenna, with switches provided, for switching the respective antenna elements into and out of the signal paths. Thus, by switching only one or a small number of the antenna elements into the signal paths, the antenna 24 can be made highly directional.

Further, the antenna may alternatively include only a small number of antenna elements, such that they form a directional antenna, with means being provided (for example, a mechanical rotational device) for altering the direction of the antenna.

Controlling the antenna 24 such that it becomes somewhat directional has the further advantage that the transmission paths from the access point 12 to one of the cellular base stations, and from the cellular base station to the access point 12 become much less affected by multipath transmissions. For example, to illustrate this, if the antenna 24 of an access point 12 is made directional, with its preferred direction pointing towards the cellular base station with which it has established a connection, the access point is less likely to be affected by reflections of the signals transmitted from the cellular base station, because these reflections are likely to be arriving from a direction that is different from the preferred direction.

Figure 4 is a block schematic diagram of an alternative communications system in accordance with an aspect of the invention. In this system, there is again provided an access point 92 located in a wireless communications environment 10, and specifically located in the coverage areas of a first base station (BS1 ) 18, a second base station (BS2) 20 and a third base station (BS3) 22, forming part of one or more cellular telephone networks.

In accordance with the invention, the access point 12 is provided with a suitable antenna 24, and radio frequency communications circuitry allowing it to establish a connection with some or all of the cellular base stations 18, 20, 22.

Figure 5 is a more detailed block schematic diagram showing the form of the access point 92. Specifically, the access point 92 includes a local area network interface 94, which may for example be an Ethernet interface, allowing one or more computers 14 or other devices to establish a connection thereto. The connections of the computers may be wired or wireless. The local area network interface 94 is connected to cellular coverage RF circuitry 28, power control circuitry 30, antenna direction control circuitry 32, and a cellular antenna 24, all of which are as described above with reference to Figure 2 and Figure 3, and therefore will not be described in more detail. In this case, the functionality of the access point 92 can simply be provided in a personal computer, for example the computer 14, which therefore may not be a portable device.

In accordance with an aspect of the invention, the access point 92 provides backhaul for data that the user of the computer 14 wishes to communicate through the access point 92.

In a preferred embodiment, the cellular coverage RF circuitry 28 is provided on a data card, for example such as a so-called 3G data card. As is known, such a data card can conventionally be inserted into a mobile device, such as a portable computer, in order to allow a user of the portable computer to communicate over the relevant cellular network. In this case, the data card can be inserted into the access point 12, or the access point 92, in order to allow a user of a device having a wireless or wired connection into the access point to communicate over the relevant cellular network. Figure 6 is a flow chart, illustrating a process in accordance with an aspect of the invention, which may be performed in, or under the control of, the controller 34 in the access point 12 or the access point 92.

The process starts at step 140, which may for example take place when the access point is first switched on, or at some subsequent time. In step 142, the controller 34 notes information from a clock, which may be an internal clock, or may be an external clock, such as a time server accessible over the internet, or a clock based on the relevant cellular system or the GPS system. For example, the controller may note information about the day of the week, and/or the time of day, or other time-related information.

In step 144, the controller performs a beam direction selection process, as will be described in more detail below, resulting in a preferred beam direction.

In step 146, the controller stores this preferred beam direction in conjunction with the time-related information. This process is then repeated at some later time. For example, in a typical

deployment, it might be suitable for the process to be repeated hourly for a learning period of one week. Thereafter, the process might be repeated at intervals, in order to take account of changes that might result from changes in the deployment of base stations in the cellular network. In general, repeating the process more often generates more information, which can be used in accordance with the invention to improve the performance of the device. Thus, in step 148, the controller 34 notes the time-related information. In step 150, the controller performs a beam direction selection process, again as will be described in more detail below, resulting in a preferred beam direction. In step 152, the controller stores this preferred beam direction in conjunction with the time-related information obtained in step 148.

Figure 7 illustrates in more detail the beam selection process. The process starts at step 170, and passes to step 172, in which a beam direction is selected. As discussed above, different beam directions can be selected by appropriate control of the controllable attenuators 52a, 52b, 52c, 52d, and 56a, 56b, 56c, 56d in the signal paths to and from the respective antenna elements 24a, 24b, 24c, 24d. For example, beam directions resembling the preferred directions of the antenna elements 24a, 24b, 24c, 24d can be selected in turn by choosing not to attenuate the signals in the signal paths to and from those antenna elements in turn.

Where the antenna is a beam switched antenna, different beam directions can be selected in turn by switching the different antenna elements into the signal paths in turn. Where the antenna is a rotatable directional antenna, different beam directions can be selected in turn by rotating the antenna.

In step 174, it is determined whether the access point 12 or 92 can establish a connection into a cellular network at the selected beam direction, with an acceptable signal quality. If so, the data rate available over that connection is measured and stored. For example, referring back to Figure 1 , even though the three base stations 18, 20, 22 may all be provided by a single mobile network operator, they may be different types of base station. For example, one may be a GSM base station, one may be a UMTS base station, and one may be a UMTS base station that allows High Speed Uplink Packet Access (HSUPA), or High Speed Downlink Packet Access

(HSDPA), or both. In that case, the UMTS base station allowing HSUPA or HSDPA will allow a higher data rate than the UMTS base station not allowing HSUPA or HSDPA, though the latter will still allow a higher data rate than the GSM base station.

The access point 12 or 92 potentially needs a high data rate connection for its backhaul requirements in order to provide high usable data rates for users such as the user 14, for example when the user 14 is using an internet connection, for example for a VoIP phone call. In such situations, it is advantageous for the access point 12 or 92 to be able to ensure that it can establish a connection to a base station that can provide a suitably high data rate connection.

By contrast, the cellular network containing the base stations 18, 20, 22 will generally be set up such that, when the access point 12 or 92 registers within the cellular network, a connection will be established with the base station that can provide the highest quality link, for example based on signal to noise ratio measurements.

Typically, however, the access point 12 or 92 would be able to establish acceptably high quality connections with several of the surrounding base stations.

Thus, in step 174, causing the antenna 24 of the access point 12 or 92 to become relatively highly directional constrains its ability to establish connections with the surrounding base stations. For each possible direction, the access point 12 or 92 may only be able to establish a connection with one of the surrounding base stations, and so the data rate over that connection can be measured.

The available data throughput can be measured in different ways. For example, with the connection set up, a file transfer of a known size can be performed, and the time taken for the transfer measured. This gives a measure of the average available data rate during the file transfer. As an alternative, the file transfer can be performed for a predetermined duration, such as 10s or 30s, and the amount of data transferred in that time can be measured. This also gives a measure of the average data rate available during the time of the file transfer, with the certainty of how long the test will take. As an alternative, or in addition, the peak data rate available during the file transfer can be measured. The measure of the available data throughput that is used can then be either the peak data rate, or some combination of the average data rate and the peak data rate. The user may be able to select the measure that is used, for example based on the way in which he intends to use the device, or this may be preset in the device. The data throughput that is available for data uploads may be different from the data throughput that is available for data downloads. Therefore, the file transfer can be performed as an upload or as a download, or both. The measure of the available data throughput that is used can then be either the uplink data throughput, or the downlink data throughput, or some average of the two. The user may be able to select the measure that is used, for example based on the way in which he intends to use the device, or this may be preset in the device.

In step 176, it is determined whether all of the possible beam directions have been tested. If not, the process returns to step 172, and continues until all of the possible beam directions have been tested. When this occurs, the process passes to step 178, in which one of the beam directions is selected. In one embodiment of the invention, software provided in the controller 34 selects the beam direction in which the highest data rate is available. In other embodiments of the invention, the controller 34 may select a beam direction, from amongst multiple beam directions providing acceptably high data rates, based on other criteria. In other embodiments, the controller 34 provides to a user, or to the management system 38, information about the available data rates based on the possible beam directions, and a suitable beam direction can then be selected. Thus, by altering the beam direction, the access point 12 or 92 effectively forces the cellular network to establish a connection between the access point 12 or 92 and a particular cellular base station, based on the requirements of the access point 12 or 92.

In one embodiment of the invention, the controller 34 also selects an alternative beam direction, that can be used to provide a connection to an alternative cellular base station, for use in the event that the connection to the first selected base station fails for any reason.

This selection of an alternative beam direction can be performed in the case of a beam definable antenna, or in the case of a beam switched antenna. In either case, the alternative beam direction is kept active, even while the first selected beam direction is in use.

As mentioned above, the controller 34 can also boost the power of transmitted and received signals by means of the power control circuitry 30, in order to make it possible for the access point 12 or 92 to establish connections to cellular base stations, even though the access point 12 or 92 may not be within the normal coverage areas of those cells.

Having performed the beam selection operation at multiple times as described with reference to Figure 6, the controller 34 has stored information about the preferred beam direction(s) at those times.

Figure 8 is a flow chart, illustrating the use of this stored information. This process starts at step 190, for example when the device is first powered up, or at a time when a user 14 is establishing a connection, and it is apparent that a wireless backhaul connection into the cellular network is required. In step 192, the controller 34 notes information from the clock, as described above. For example, the controller may note information about the day of the week, and/or the time of day, or other time-related information.

Then, in step 194, the controller 34 uses the stored information about the preferred beam direction(s) to select one of the stored preferred beam directions as its preferred beam direction at that time. This selection is based on the recognition that the loading conditions of a cellular network vary over time. Typically, for example, cellular basestations that are located in business districts might be heavily loaded during weekdays, but might be lightly loaded during evenings and weekends; cellular basestations that are located in entertainment districts might be heavily loaded during evenings, but might be lightly loaded during the daytime; and cellular basestations that are located in residential areas might be heavily loaded during evenings and weekends, but might be lightly loaded during weekdays. It is also recognized that the loading on a cellular basestation can have a significant effect on the data rate that can be achieved by any one user. That is, the basestation might have a maximum total data rate, which must be shared amongst all active users. In that situation, if a user can select a lightly loaded basestation, he might be able to achieve a higher data rate than if he selects a heavily loaded basestation.

In such a situation, the access point 12 or 92 might be located between a number of cellular basestations, which have different loading patterns. For example, the access point 12 or 92 might be located between a first cellular basestation located in a business district, a second cellular basestation located in an entertainment district, and a third cellular basestation located in a residential area. In that case, there might be expected to be a pattern whereby one particular basestation typically provides the highest available data rate at certain times of the day or week, while another basestation typically provides the highest available data rate at other times of the day or week.

Thus, in step 194 of the process shown in Figure 8, the controller 34 is able to use any such pattern to select one of the stored beam directions, depending on the particular time of the day, or day of the week. More specifically, the controller 34 is able to select the stored beam direction that was previously found to give the highest data rate at the corresponding time of the day, or day of the week.

As a precaution, the process then passes to step 196, in which the available data rate is measured, and compared with the data rate that was achieved when that stored beam direction was originally selected, by the selection process described with reference to Figure 6. For example, if this comparison shows that the available data rate on the downlink is, say, 20% lower than the available data rate that was achieved on the downlink during the original selection process, this might indicate that the access point has been moved or rotated, or that there has been a significant change in the cellular network, with the result that the previously selected beam direction is no longer the most appropriate one.

Thus, if it is determined in step 196 that the available data rate is within an allowable range, for example greater than 80% of the previously measured data rate, then the process passes to step 198 and ends, and the operation of the access point can begin with that selected beam direction. However, if it is determined in step 196 that the available data rate is not within the allowable range, then the process passes to step 200, in which a new beam selection process, as shown in Figure 6, is started. Thus, as time progresses, the selected beam direction can then switch to the beam direction that is appropriate for that particular time of the day or week, such that the selected beam direction at any particular time is the beam direction that has previously been found to give the highest data rate at a corresponding time in the past. There is thus provided a system in which a cellular network can be used to provide a high data rate service for an access point at a particular location, without requiring the access point to check the available data rates before setting up the backhaul link.

Claims

1 . A method of operating an access point, wherein the access point is adapted to allow access from at least one user device, wherein the access point comprises radio frequency transceiver circuitry for communicating over a wireless link with a base station selected from a plurality of available base stations, and wherein the access point has a plurality of possible antenna beam directions;

the method comprising:

repeatedly determining a preferred one of said available beam directions, based on available data rates at different times; and

at a particular time of use, selecting a beam direction for use, based on the particular time, wherein the selected beam direction is the preferred one of said available beam directions at a time corresponding to the particular time.

2. A method as claimed in claim 1 , wherein the access point allows access from at least one user device over a second wireless link.

3. A method as claimed in claim 2, wherein the access point allows access from at least one user device over a WiFi link.

4. A method as claimed in claim 2, wherein the access point allows access from at least one user device over a WiMax link.

5. A method as claimed in claim 1 , wherein the access point allows access from at least one user device over a wired local area network.

6. A method as claimed in any preceding claim, wherein the step of determining the preferred one of said available beam directions comprises determining the beam direction that provides the highest available data rate at a time of determination.

7. A method as claimed in any preceding claim, comprising:

repeatedly determining at different times of day a preferred one of said available beam directions, based on available data rates at said different times of day; and

at a particular time of use, selecting a beam direction for use, based on the particular time of day, wherein the selected beam direction is the preferred one of said available beam directions determined on a previous occasion at the particular time of day.

8. A method as claimed in any preceding claim, comprising:

repeatedly determining at different times of the week a preferred one of said available beam directions, based on available data rates at said different times of the week; and

at a particular time of use, selecting a beam direction for use, based on the particular time of the week, wherein the selected beam direction is the preferred one of said available beam directions determined on a previous occasion at the particular time of the week.

9. A method as claimed in any preceding claim, further comprising:

after selecting a beam direction for use, confirming that an available data rate is within a range based on the available data rate at the time that said beam direction was determined to be the preferred one of said available beam directions at the time corresponding to the particular time.

10. An access point, comprising:

a first access interface, adapted to allow access from at least one user device; radio frequency transceiver circuitry for communicating over a wireless link with a base station selected from a plurality of available base stations;

an antenna system, having a plurality of available beam directions; and control circuitry, for determining data rates available over wireless links with said plurality of available base stations,

wherein the access point is configured to:

repeatedly determine a preferred one of said available beam directions, based on available data rates at different times; and

at a particular time of use, select a beam direction for use, based on the particular time, wherein the selected beam direction is the preferred one of said available beam directions at a time corresponding to the particular time.

1 1 . An access point as claimed in claim 10, wherein the access point allows access from at least one user device over a second wireless link.

12. An access point as claimed in claim 1 1 , wherein the access point allows access from at least one user device over a WiFi link.

13. An access point as claimed in claim 1 1 , wherein the access point allows access from at least one user device over a WiMax link.

14. An access point as claimed in claim 10, wherein the access point allows access from at least one user device over a wired local area network.

15. An access point as claimed in one of claims 10 to 14, configured to determine the preferred one of said available beam directions by determining the beam direction that provides the highest available data rate at a time of determination.

16. An access point as claimed in one of claims 10 to 15, configured to:

repeatedly determine at different times of day a preferred one of said available beam directions, based on available data rates at said different times of day; and

at a particular time of use, select a beam direction for use, based on the particular time of day, wherein the selected beam direction is the preferred one of said available beam directions determined on a previous occasion at the particular time of day.

17. An access point as claimed in one of claims 10 to 16, configured to:

repeatedly determine at different times of the week a preferred one of said available beam directions, based on available data rates at said different times of the week; and

at a particular time of use, select a beam direction for use, based on the particular time of the week, wherein the selected beam direction is the preferred one of said available beam directions determined on a previous occasion at the particular time of the week.