GB2414137A

GB2414137A - Control of Antenna Line Device.

Info

Publication number: GB2414137A
Application number: GB0410543A
Authority: GB
Inventors: Jonathan Rigelsford
Original assignee: University of Sheffield
Current assignee: University of Sheffield
Priority date: 2004-05-12
Filing date: 2004-05-12
Publication date: 2005-11-16
Also published as: GB0410543D0

Abstract

A base station (1) for a communications network (such as a mobile telephone network, a cellular telephone network, or some other portable transceiver network) has an antenna (2); an antenna line device (3) connected to the antenna; and an interface unit (4) connected to the antenna line device. The interface unit (4) includes a receiver adapted to receive wireless control signals (5), and adapted to control the antenna line device (3) (i.e. to generate and provide ALD control signals to the ALD) according to the received wireless control signals (5).

Description

Control of Antenna Line Devices

Field of the Invention

The present invention relates to the control of antenna line devices, and in particular, although not exclusively, to the control of antenna line devices incorporated in base stations of a mobile telephone communications network.

Background to the Invention

Mobile telephone networks (which are also known as cellular telephone networks) typically comprise a number of base stations (also known as base transceiver stations, or BTSs) distributed over an area. These base stations provide network coverage in that they receive broadcast signals (wireless signals) transmitted from mobile telephones in their vicinity, and also transmit signals, for reception by mobile telephones in their vicinity, originating fom other telephones on the same, or a different, network. The base stations are interconnected by suitable means, and thus provide a system for relaying signals between telephones covered by the network.

Each base station typically comprises a number of antennae, for transmitting the wireless signals to, and receiving the wireless signals from, mobile telephones. These antennae are mounted on a mast (or tower) and are directional, at least to some degree, in that their radiation patterns are not isotropic. Their beams have a maximum in some direction, the main beam direction, or plane. Thus, the coverage of each antenna is in part determined by the geometry of its installation on the tower.

This brings us to the concept of tilt. Tilt (which is also referred to as beamtilt, tilt angle, and downtilt) can be defined generally as the angle of inclination of the antenna's main beam direction to a horizontal plane. A positive tilt angle means that the antelma's beam is directed below the horizontal plane, and a negative tilt angle means that the beam direction is above the horizontal. A mechanical tilt of the antenna can be set on installation (i.e. when the antenna is mounted on the tower).

It is also known to adjust the antenna tilt electrically, independently of any mechanical tilt already set. To do this, the base station includes a remote electrical tilt unit (RET unit), which may also be referred to as an antenna drive unit. The RET unit is connected to the antenna, and is controlled by an interface unit. By controlling the electrical signal(s) delivered to the antenna, the RET device is used to vary the antenna tilt electrically (i.e. without any physical movement of the antenna or its components, relative to the tower). Tllus, the interface unit, by providing suitable control signals to the RET device, is able to control the electrical tilt. In other words, in base stations with a RET facility the electrical tilt is variable and controllable.

A RET device is just one type of antenna line device (ALD) used in base stations. In general, an ALD is an addressable physical device which may be connected to an antenna and controlled to adjust or measure some operational characteristic or property of the antenna. The RET device is controllable to adjust the antenna beam direction, but other ALDs include amplifiers and boosters for adjusting antenna power output and received signal amplification, and voltage standing wave ratio (VSWR) measuring units.

A typical base station may include a rougher of AT,Ds, and an interface unit to control them. The Antenna Interface Standards Group (AISG) has published a document defining a standard (AISG1) which is a standard data interface at an antenna line device by means of which functional parameters of the device can be controlled. An ALD confonning to this standard is referred to as an AISG device. Similarly, an interface unit adapted to control an AISG device may be referred to as an AISG interface unit. Such an interface unit may also be referred to as an AISG primary, with the AISG ALDs being AISG secondaries. The current version of the AISG1 standard can be obtained from the AISG website at "http://www.ais. org.uk/".

In the past, to adjust a base station ALD, either an engineer had to visit the base station site and physically connect a control unit (e.g. laptop computer) to the interface unit, or a dedicated, hard-wired control link was provided to the interface unit from a remote control centre. Clearly' the fonner involved inconvenience, as the engineer had to visit the site and gain entry through any security fencing, and required the provision of a suitable connector (e.g. socket) at the interface unit, which could compromise the security of the unit. The second option added to the complexity and cost of the communications network infrastructure.

It is therefore an object of embodiments of the invention to provide improved apparatus and methods for controlling antenna line devices. Embodiments of the present invention aim to overcome, at least partially, one or more of the problems

associated with the prior art.

Summary of the Invention

According to a first aspect of the present invention there is provided a base station for a communications network (such as a mobile telephone network, a cellular telephone network, or some other portable transceiver network), the base station comprising: an antenna; an antenna line device connected to the antenna; and an interface unit connected to the antenna line device, the interface unit including a receiver adapted to receive wireless control signals, and being adapted to control the antenna line device (i.e. to generate and provide ALD control signals to the ALD) according to the received wireless control signals.

Thus, advantageously, the ALD may be adjusted remotely, for example to adjust electrical tilt, without an engineer having to gain physical access to the interface unit.

No external comcctor is required on the interface unit, improving its security and integrity. Also, no hard-wired control link into the interface unit is required.

Preferably, the wireless control signals are encrypted and the interface unit further comprises decryption means for decrypting received wireless control signals.

In certain preferred embodiments the wireless control signals are mobile telephone signals (e.g. transmitted from a mobile telephone and relayed to the receiver by a mobile telephone network), and the the receiver comprises a mobile telephone modem, e.g. a GSM/3G modem. GSM is the Global System for Mobile communications, a digital wireless standard, and is currently the most widely used digital mobile phone system. 3G refers to the so-called third generation protocols which support higher data rates than previous standards.

Preferably, the receiver further comprises a SIM (Subscriber Identity Module) card.

Advantageously, the wireless control signals are in SMS format (the Short Message Service fonnat, available on digital GSM networks and allowing text messages to be sent and received via a network operator's message centre, to of from a mobile phone, or front the inten1et, Using an 'SMS gateway" website).

In certain preferred embodiments, the receiver is adapted to receive said wireless control signals directly from a mobile telephone. To do this, the receiver may comprise an infra-red receiver, and the wireless control signals may be infra-red signals.

Advantageously, wireless control signals may be in bluetooth format, the well-known short-range wireless communications fonnat.

The interface unit may be adapted to receive the wireless control signals in a first format, and to generate and provide, to the antenna line device, corresponding antenna line device control signals in a second format. For example, the first format may be SMS, and tl1e second forn1at may be ATSGI compatible.

In certain preferred the antenna line device conforms with interface standard AISG1.

The antenna line device may, for example, be a remote electrical tilt unit; an antenna drive unit, an amplifier, a tower-mounted amplifier, a booster, a tower-mounted booster, or a VSWR measuring unit.

The base station may comprise a plurality of antenna line devices, with the interface unit being adapted to control each antenna line device according to the wireless control signals received by the receiver. Typically, the antenna line devices are individually addressable, and individually controllable, by the interface unit.

In certain preferred embodiments the interface unit comprises a wireless transceiver, the wireless transceiver providing the receiver, and also enabling the base station to send wireless communications to the controlling unit/ mobile phone.

Another aspect of the invention provides a wirelessly controllable base station in combination with a controller (preferably portable) operable to transmit the wireless control signals. Preferably, the controller is a mobile telephone.

Yet another aspect of the invention provides an interface unit for controlling an antenna line device which conforms to interface standard AISG1, the interface unit comprising a receiver adapted to receive wireless control signals, and to generate corresponding antenna line device control signals for controlling an AISG1 antenna line device.

Again, the receiver preferably comprises a mobile telephone modem adapted to receive the wireless control signals in the fond of mobile telephone signals. The receiver may be adapted to receive the wireless control signals in SMS format.

The wireless control signals may be infra-red signals, and may be in Bluetooth format.

Another aspect of the invention provides a communication network base station and control system, the system comprising: a base station comprising an antenna, an antenna line device connected to the antenna, and an interface unit corrected to the antenna line device, a mobile telephone operable to transmit wireless control signals; a call centre or exchange arranged to receive said wireless control signals, and being connected to the base station interface unit by a first connection means, the call centre or exchange being responsive to receipt of a wireless control signal from the mobile telephone to send a corresponding signal to the interface unit via the first connection means, and the interface unit being responsive to the corresponding signal to generate and provide a corresponding antenna line device control signal to the antenna line device.

The call centre or exchange may, for example, be adapted to receive the wireless control signals directly, or may receive them indirectly via a second connection means.

The first connection means may, for example, be an all-wired connection, an all- wireless connection, or a combination of hard-wired and wireless links. The second connection means comprises at least one wireless link (the transmission of the wireless control signal from the mobile phone to some receiver). The second connection means may comprise further wireless and/or hard-wired links.

The mobile telephone is preferably operable to transmit the wireless control signals in SMS format, and the call centre is an SMS centre (message centre).

Another aspect of the invention provides a base station for a communications network (such as a mobile telephone network, a cellular telephone network, or some other portable transceiver network), the base station comprising: an antenna; an antenna line device connected to the antenna; and an interface unit connected to the antenna line device, the interface unit comprising means for enabling a telephone connection to he made to the interface unit, means for providing a audible menu to a connected telephone, processing means arranged to process a verbal selection from the menu (i.e. a verbal response) from a connected telephone and to generate and provide to the antenna line device an antenna line device control signal according to the verbal selection.

Yet another aspect provides a method of controlling an antenna line device (for example, an antenna line device of a communications network base station), the method comprising the steps of: transmitting a wireless control signal from a mobile telephone; receiving the wireless control signal at an interface unit; generating an antenna line device control signal according to the received wireless control signal; and controlling the antenna line device with the antenna line device control signal.

Preferably, the method further comprises the step of relaying the transmitted wireless control signal from the mobile telephone to the interface unit via a mobile telephone network, or the step of transmitting comprises transmitting the wireless control signal as an infra-red signal. The wireless control signals may be in Bluetooth format.

Another aspect provides a method of controlling an antenna line device (for example, an antenna line device of a communications network base station), the method comprising the steps of: transmitting a wireless control signal (e.g. in SMS format) from a mobile telephone to a call centre or exchange; sending a corresponding signal fiom the call centre or exchange to an interface unit via a wired link; generating, at the interface unit, an antenna line device control signal according to the corresponding signal received from the call centre or exchange; and controlling the antenna line device with the antenna line device control signal.

A further aspect provides a method of controlling an antenna line device (for example, an antenna line device of a communications network base station), the method comprising the steps of: establishing a telephone connection to an interface unit (preferably located at the base station); presenting, to a connected telephone, an audible menu of commands; responding to the menu with a verbal response; processing the response; and controlling tile antenna line device according to the response.

In the above methods, the step of controlling the antenna line device may, for example, comprise controlling the antenna line device to adjust a tilt angle of an anteilila connected to the antenna line device.

Brief Description of the Drawings

Embodiments of the invention will now be described with reference to the accompanying drawings, of which: Fig. 1 is a schematic representation of a base station and control system embodying the invention; Fig. 2 is a schematic representation of a base station and controller embodying the invention; Fig. 3 is a schematic representation of an ALD control system embodying the invention; and Figs. 4-8 are schematic representations of other ALD control systems embodying the invention.

Detailed Description of the Preferred Embodiments

Referring now to figure l, a first embodiment of the invention comprises a communications network base station I and a hand-held wireless controller 7. The base station l comprises: an antenna 2 mounted On a tower/mast 6; an antenna line device 3 connected to the antenna; and an interface unit 4 connected to the antenna line device. The tower 6 and interface unit 4 are located on a base 11. The interface unit 4 includes a receiver, having a receiver antenna 41, adapted to receive wireless control signals 5. The interface unit 4 is adapted to control the antenna line device 3 (i.e. the interface unit is arranged to generate and provide ALD control signals to the ALD) according to the received wireless control signals 5. In this example the ALD 3 is a RET unit, and thus the interface controls the ALD to electrically adjust the tilt angle 22 between the antenna's beam direction 21 and the horizontal H. Adjustment of the tilt angle is indicated generally by arrow A. The wireless control signals are initially transmitted from the antenna 71 of the portable controller 7, and are relayed to the interface unit antenna 41 via a communications network 51.

Fig. 2 shows an alternative embodiment in which the portable controller 7 includes an infra-red (JR) transmitter 72. The controller 7 is operable to transmit short-range encrypted IR wireless control signals 5 directly to an IR receiver 43 in the interface unit. The interface unit includes a decrypter which decrypts the received signals. The interface unit then generates, and provides to the ALD, corresponding control signals.

In this example the ALD is an amplifier and the interface unit controls the amplifier gain. The ALD may be located on, or close to' the base 11, or may be tower- mounted.

Fig. 3 illustrates an embodiment which is a system for controlling antenna line devices. The system comprises a controller 7 having a wireless communications cormection 5,52 to an interface unit 4, having a wireless transceiver, and suitable data and power conversion to control a single or plurality of ALDs 3. Data is securely transmitted from the controller unit 7 to the interface unit 4, each unit having suitable encryption/decryption. The wireless signals for controlling the ALDs are denoted by reference numeral 5. The interface unit transceiver can also send wireless signals 52 back to the controller 7, for example to confirm that a control operation has been carried out, or to provide the control unit with data on the state of the various ALDs, and/or the current operational characteristics of one or more antennae connected to the ALDs. The control unit 7 and interface unit 4 comprise respective transceiver antennae 71, 41 for transmitting and receiving the wireless signals.

Figure 4 illustrates another ALD control system. In this example, the control units 7 are mobile telephones, and the control signals 5 sent to the interface unit are SMS based. The interface unit 4 is an on-site ALD Primary control station including a GSM/3G modem and a SIM card 43. The systerr. utilises a simplified command set based on text, and that set can be translated into AISG commands by the primary station. This system provides numerous advantages. Although the illustrated system utilises GSM/3G, it can be extended to any mobile network system, as long as SMS is available.

Implementation is mostly software [based, and GSM/GPRS modules are on the market already. SiM usage provides a better security in the system, since it is possible to block or Galore messages from a non-registered number. (The operator-phone nmler list can be easily managed by the primary or a central system and may as well be extended to use the GSM HER listings). Furthermore, no software development is necessary for the handset; to control the ALD all the user has to do is send standard text messages, containing commands selected from the command set. Thus, there are low development costs to implement the system.

The system does however have associated with it higher deployment costs: GSM/3G modems are required for each primary station. Also, the system requires GSM/3G coverage to work. This means: it may not be suitable for installation. This is not too great a problem since, in installation, someone shill have to be on-site, but it also means that the installer has to check that this portion of the system is working satisfactorily before leaving the site (in other words, it adds an extra procedure for installation). Lastly, one could be left with a non-operating system if the adjustments made by a sent command leave the area without coverage.

Figure 5 shows another ALD control system, this time utilising wireless SMS based control signals 5, and a fixed line to the interface unit 4 from an SMS centre 53. The system comprises an on-site primary station 4 with a fixed line (telephone, via public switched telephone network 54 and phone 44, or Ethernet 55) connected to the messaging centre 53. It utilises a simplified corrunand set based on text that can be translated into AISG commands by the primary station 4. It provides the same advantages as the system of fig. 4, plus the additional advantage that a bad adjustment of the system can not render it non-operational, since although the area coverage might be affected, the connection of the interface unit 4 to the messaging centre is done by wired media, hence adjustments are still possible. Also, this system involves lower deployment costs as no SIM cards are required for each AISG primary (interface unit 4).

Possible disadvantages, to be borne in mind, are that system development involves a deeper knowledge of the messaging system architecture, and the link between the SMS centre and the primary station must be set up correctly during on-site installation. Also, if a telephone connection is used, the system is more complex in terms of communication management, since the messaging centre should dial up the on-site primary station, and then one of these two possibilities should occur: hold the communication and wait for the response on the same call; or hang up and then the primary station dials-up the messaging centre to send the acknowledgement to the operator's handset. If an Ethernet connection is used, then problems may arise from having a penlanent comection to the on- site primary and how this link is managed: this could mean using TCP/IP (Transmission Control Protocol over Internet Protocol) to mount the textbased command set and then translate that into AISG commands.

Figure 6 shows an ALD control system incorporating a wireless interface, using IR or Bluetooth modules of a handset 7. The controllers 7 are Bluetooth/IR capable mobile phone handsets, and the base station interface unit 4 includes a Bluetooth/IR interface (i.e. on the on-site primary station). This arrangement provides the advantages that the system is independent of a specific mobile network. The link and its management is established by this application (i.e. IIardshaking, authentication, and link data conveyance are defined). To adjust ALD 3 parameters, there is no need to provide operators with laptops to perform the changes; these can be made by the operators using their handsets 7, although the operators still need to go on site (i.e. make a site visit) to perfonn maintenance and adjust the ALDs, because the wireless communication is only short range.

With systems generally in accordance with that shown in fig. 6, two approaches can be distinguished. Firstly, one can have an intelligent application on the handset, in which case heavy development is required on the handset side, as the primary software is in the handset. This reduces the work on the ALD side, since it would not be necessary to have powerful hardware on-site, just a type of converter that extracts the AISG information from the Wireless link and translates it, for example to RS485/coax.

In general, this involves a more expensive development but might yield a cost effective solution for BTS equipment control (although visits might still be necessary due to limited coverage, it still is better than current solutions based on PC environments). The second approach is to provide the intelligence on an on-site primary station with a IRJBluetooth interface. In this case, the handset side would be very similar to the SMS solution, but instead of sending information through the mobile network, it sends it through the local link. This still provides a cost effective solution in teens of equipment distributed to operators, but requires a relatively powerful on-site primary station.

Figure 7 shows another ALD control system, using a DTMF (Dual Tone MultiFrequency) Interface. It represents a DTMF application to control ALDs, such as RET devices. The system comprises a phone line 47, a modem or a DTMF decoder 46, and a voice based messaging system (voice based menu and voice based action confirmation) implemented by the interface unit. To control the ALDs, a user dials in to the interface unit from a telephone 7 Thus' a telephone link is established via phone line 47. The user is then presented with a menu, makes a selection, and the ALDs are controlled accordingly. This system represents a simple approach, in that one can use any phone line to communicate to a given BTS and control its equipment.

A fairly powerful system is required on-site (i.e. in the interface unit) to handle the voice messages, menus and decode the information to translate it into an AISG message, and then translate the AISG response to a voice message.

Figure 8 shows another ALD control system embodying the invention. An exchange 9, such as a Private Branch Exchange (PBX), is connected to the interface unit 4 of a base station I by means of a first connection 91, which may be wired, wireless, or a combination of wired and wireless links. The exchange 9 is adapted to receive wireless control signals 5, originating from a mobile phone 7, via second connection means 92. In r esponse to r eceiving the wireless control signals, the exchange sends corresponding signals, via first connection means 91, to the interface unit 4, which in turn generates and sends corresponding ALD control signals to the ALD 3. It will be appreciated that this, and other embodiments of the invention, enable wireless control of ALDs to be effected from anywhere in the world with mobile telephone network coverage.

Claims

Claims 1. A base station for a communications network, the base station

comprising: an antenna; an antenna line device connected to the antenna; and an interface unit connected to the antenna line device, the interface unit including a receiver adapted to receive wireless control signals, and being adapted to control the antenna line device according to the received wireless control signals.
2. A base station in accordance with claim 1, wherein the wireless control signals are encrypted and the interface unit further comprises decryption means for decrypting received wireless control signals.
3. A base station in accordance with any preceding claim, wherein the wireless control signals are mobile telephone signals.
4. base station in accordance with any preceding claim, wherein the receiver comprises a mobile telephone modem.
5. A base station in accordance -with claim 3 or claim 4, wherein the receiver further comprises a SIM card.
6. A base station in accordance with any preceding claim, wherein the wireless control signals are in SMS format.
7. A base station in accordance with arty preceding claim, wherein the receiver is adapted to receive said wireless control signals directly from a mobile telephone.
8. A base station in accordance with any preceding claim, wherein said receiver comprises an infra-red receiver and said wireless control signals are infra-red signals.
9. A base station in accordance with any preceding claim, wherein said wireless control signals are in Bluetooth format.
10. A base station in accordance with any preceding claim, wherein the interface unit is adapted to receive the wireless control signals in a first format, and to generate and provide, to the antenna line device, corresponding antenna line device control signals in a second fon1lat.
11. A base station in accordance with any preceding claim, wherein the antenna line device conforms with interface standard AISG1.
12. A base station in accordance with any preceding claim' wherein the antenna line device is selected from a list comprising: a remote electrical tilt unit; an antenna drive unit; an amplifier; a towermounted amplifier; a booster; a tower-mounted booster; and a VSWR measuring unit.
13. A base station in accordance with any preceding claim, and comprising a plurality of said antenna line devices, the interface unit being adapted to control each antenna line device according to said wireless control signals received by the receiver.
14. A base station in accordance with arty preceding claim, wherein the interface unit comprises a wireless transceiver, the wireless transceiver comprising said receiver.
15. A base station in accordance with any preceding claim, in combination with a controller operable to transmit said wireless control signals.

16. A combination of base station and controller in accordance with claim 15, wherein the controller comprises a mobile telephone.
16. An interface unit for controlling an anterma line device which conforms to interface standard AISG1, the interface unit comprising a receiver adapted to receive wireless control signals, and to generate corresponding antenna line device control signals for controlling an AISG1 antenna line device.
17. An interface unit in accordance with claim 16, wherein the receiver comprises a mobile telephone modem adapted to receive said wireless control signals in the form of mobile telephone signals.
18. An interface unit in accordance with claim 16 or claim 17, wherein the receiver is adapted to receive said wireless control signals in SMS format.
19. An interface unit in accordance with claim 16, wherein said wireless control signals are infra-red signals.
20. An interface unit in accordance with claim 16 or claim 19, wherein the receiver is adapted to receive said wireless control signals in Bluetooth format.
21. A communication network base station and control system, the system COlllprl Slllg: a base station comprising an antenna, an antenna line device connected to tile antenna, and an interface unit connected to the antenna line device, a mobile telephone operable to transmit wireless control signals; a call centre or exchange arranged to receive said wireless control signals, and being connected to the base station interface unit by a first connection means, the call centre or exchange being responsive to receipt of a wireless control signal from the mobile telephone to send a corresponding signal to the interface unit via the first connection means, and the interface unit being responsive to the corresponding signal to generate and provide a corresponding antenna line device control signal to the antenna line device.
22. A system in accordance with claim 21, wherein the mobile telephone is operable to transmit said wireless control signals in SMS format.
23. A system in accordance with claim 22, wherein said call centre is an SMS centre.
24. A base station for a communications network, the base station comprising: an antenna; an antenna line device connected to the antenna; and an interface unit connected to the antenna line device, the interface unit comprising means for enabling a telephone comection to be made to the interface unit, means for providing a audible menu to a connected telephone, processing means arranged to process a verbal selection from the menu from a connected telephone and to generate and provide to the antenna line device an antenna line device control signal according to the verbal selection.
25. A method of controlling an antenna line device, the method comprising the steps of: transmitting a wireless control signal from a mobile telephone; receiving the wireless control signal at an interface unit; generating an antenna line device control signal according to the received wireless control signal; and controlling the antenna line device with the antenna line device control signal.
26. A method in accordance with claim 25, further comprising the step of relaying the transmitted wireless control signal from the mobile telephone to the interface unit via a mobile telephone network.
27. A method in accordance with claim 25, wherein the step of transmitting comprises transmitting the wireless control signal as an infra-red signal.
28. A method in accordance with claim 25 or claim 27, wherein the step of transmitting comprises transmitting the wireless control signal in Bluetooth format.
29. A method of controlling an antenna line device, the method comprising the steps of: transmitting a wireless control signal from a mobile telephone to a call centre or exchange; sending a corresponding signal from the call centre or exchange to an interface unit via a wired link; generating, at the interface unit, an antenna line device control signal according to the corresponding signal received from the call centre or exchange; and controlling the antenna line device with the antenna line device control signal.
30. A method in accordance with claim 29, wherein the step of transmitting comprises transmitting the wireless control signal in SMS format.
31. A method of controlling an antenna line device, the method comprising the steps of: establishing a telephone connection to an interface unit; presenting, to a connected telephone, an audible menu of commands; responding to the menu with a verbal response; processing the response; and controlling the antenna line device according to the response.
32. A method in accordance with any one of claims 25 to 31, wherein the step of controlling the antenna line device comprises controlling the antenna line device to adjust a tilt angle of an antema connected to the antenna line device.
33. A base station substantially as here;nbefore described with reference to the accompanying drawings.
34. A base station and control system substantially as hereinbefore described with reference to the accompanying drawings.
35. A method of controlling an antenna line device substantially as hereinbefore described with reference to the accompanying drawings.