WO2003096625A1

WO2003096625A1 - Automatic installation process for wireless communication system

Info

Publication number: WO2003096625A1
Application number: PCT/GB2003/001770
Authority: WO
Inventors: Robert Edmund Todd
Original assignee: Cedardell Ltd
Current assignee: Cedardell Ltd
Priority date: 2002-05-11
Filing date: 2003-04-25
Publication date: 2003-11-20
Anticipated expiration: 2004-11-11
Also published as: CA2485612A1; AU2003227882A1; GB0210857D0; EP1504570A1

Abstract

A wireless communication system is arranged in a generally linear chain and is initially set up by providing a control module (100) and a first communications module (101). The communications module (101) transmits a radio frequency wireless message to the control module (100), and the control module (100) has address number (0), and the communications module (101) is allocated address number (1), so that it communicates directly with the control module (100). When a second communications module (102) is to be inserted into the system in the position shown in figure (5)(i.e. at the end of the chain remote from the control module (100)), the new module (102) is caused to emit a message in a set-up mode. Initially, the existing module (100, 101) which received the message with the strongest signal intensity (module (101) in the case of figure (5), because of its proximity to the new module (102)) is identified. The new module (102) is then caused to communicate directly with the existing module (101) by allocating address number (2) to the module (102).

Description

AUTOMATIC INSTALLATION PROCESS FOR

WIRELESS COMMUNICATION SYSTEM

The present invention relates to a method of inserting one or more communications modules into a wireless communication system having at least one control module and a plurality of communications modules, wherein the system transmits wireless messages directly or indirectly between pairs of modules. The invention relates particularly, but not exclusively, to a method of inserting one or more communications modules into a system in which a high degree of reliability is required, such as in a security or fire alarm system.

Wireless communication systems are known in which one or more control modules transmit wireless messages around the system, either directly or indirectly, via successive radio frequency communications modules, each of which is designed to receive a message and transmit the message onwards in the system to a '^control module or to a further communications module. Each module is allocated a predetermined position in the order of message transmission. This enables wireless -messages to be relayed across relatively large distances by indirect communica ion, the messages being relayed via modules, without the need for high power transmitters , which in certain countries are subject to fairly stringent licensing requirements .

Known communications systems of this type suffer from the drawback that if one of the communications modules is removed, reliability of message transmission paths around the system can no longer be relied upon, or the communications modules must be reconfigured, which is a considerably time consuming process. Also, if a new communications module is inserted into the system, it is a fairly labourious process to reconfigure the other units in the system (i.e. reallocate their positions in the order of message transmission) in order to take account of the new unit so that the new unit is given the most effective position in the order of message transmission. In particular, in broadcast systems it is usually necessary to program into the new unit system numbers, unit numbers, time identifiers and so on. The programming of these parameters is relatively difficult for untrained personnel, thus increasing the cost and difficulty of operating the system. These numbers are sometimes inserted by means of software, but most often by means of a series of switches (of which there are usually eight or sixteen) , each of which needs to be set in one of two positions by personnel. This clearly makes setting up the system more labour intensive and therefore increases its ^'cost.

An attempt to overcome this problem is disclosed in our International Patent Application No. WO 01/15112. In this arrangement, a new unit to be installed in the system is only installed if it can communicate with two existing modules which were configured to communicate directly with each other prior to installation of the new module.

Although this arrangement offers significant improvements over prior arrangements and operates well when the modules of the system are arranged in a generally circular loop, the system suffers from the drawback that problems arise if the modules are arranged in a linear chain covering a large distance, as illustrated in figures 1 to 4. In particular, figure 1 shows a communication system in which a control module 1 communicates by radio frequency wireless signals with a communications module 2. The control module 1 is allocated address number 0, and the communications module 2 is allocated address number 1. By also allocating an address one higher than the number of communications modules 2 in the system to the control module 1 (address number 2 in the case of figure 1) , this ensures that messages are communicated around the loop between modules of successive addresses and back to the control module 1.

When a new communications module 3 is to be inserted into the system shown in figure 1, the new module 3 must firstly be able to communicate directly with at least two existing modules 1,2 for it to be installed at all. If the new module can communicate with the control module 1 and existing communications module 2, it is placed between the two existing modules in order of communication. In other words, the system is modified to the system of figure 2 in which the new communications module 3 is now allocated address number 1, the existing communications module 2 has its address incremented to 2, and the control module 1 is allocated addresses 0 and 3.

Referring now to figure 3, when a new communications module 4 is to be inserted at the end of the linear chain, remote from the control module 1, of the system shown in figure 2, if the new module 4 can communicate with existing modules 2 and 3 but not control module 1, since the existing communications modules have addresses 1 and 2, the new module 4 is placed between those existing modules 2,3 in the order of message transmission. In other words, existing module 3 retains address number 1, new module 4 is allocated address number 2, and the address of existing module 2 is incremented to 3, the other address of the control module 1 being incremented to 4. When a further communications module 5 is added to the end of the chain, as shown in figure 4, by an extension of the process described above, if the new module 5 communicates directly with existing modules 3 and 4 it must therefore be placed in order of communication between those two modules. The address of existing module 3 therefore remains unchanged at address number 1, the new module 5 is allocated address number 2, and addresses of existing modules 4 and 2 are incremented to address numbers 3 and 4 respectively. The control module 1 is allocated addresses numbers 0 and 5.

It can be seen from figure 4 that a situation builds up in which messages communicated from left to right as shown in figure 4 are transmitted along the chain via control and communications modules 1, 3, 5, located at alternate positions along the linear chain, and messages transmitted from right to left are communicated via alternate communications modules 4, 2. However, because of the large distances over which messages must be transmitted between successive modules, problems arise if a communications module, say 3, should fail, since the control module 1 must then communicate with the next highest address, i.e. module 4 with address 2, and must therefore transmit messages directly across a distance of four module spacings directly with control module 5. A situation can therefore easily arise in which modules are out of range of each other.

Preferred embodiments of the present invention seek to overcome the above disadvantages of the prior art.

According to the present invention, there is provided a method of inserting a communications module into a wireless communications system comprising at least one control module and a plurality of first communications modules, wherein the system is adapted, when in a communication mode, to transmit wireless messages sequentially between modules, and wherein each said first communications module is adapted to receive a wireless message and transmit that message to a further first communications module or to a said control module, the method comprising: -

(i) causing a second communications module, which is to be inserted into the system, to transmit at least one first message in a set-up mode;

(ii) identifying the first communications module which receives the or each said first message with the highest signal intensity;

(iii) causing said second communications module, when in said communication mode, to communicate directly with a first said communications module with received a said first message with the highest signal intensity. By causing the second communications module, which is to be inserted into the system, to communicate directly with the first communications module which received a message from it with the highest signal intensity, without forcing the second communications module to communicate directly with two existing first modules which communicated directly with each other prior to installation of the second communications module into the system, this provides the advantage that in the case of modules being arranged in a generally linear chain extending over a large distance, modules are not required to communicate directly with other modules over large distances, and the invention ensures that any new module can communicate effectively with an existing module.

In a preferred embodiment, the method further comprises the step of only causing said second communications module to be installed in the system if a said first message is received by at least two said first communications modules.

This provides the advantage of ensuring greater system integrity. For example, if the second communications module can communicate with more than one first communications module, messages can still be transmitted around the system even if the first communications module, which received the first message with greatest signal intensity, should fail.

The method may further comprise the step of only causing said second communications module to be installed in the system if a said first message is received by said first communications module which received the message with greatest signal strength and a further said first communications module adapted to communicate directly with said first communications module which received the signal with greatest signal strength.

The method may further comprise the step of causing a third communications module, which is to be inserted into the system, to transmit at least one second message in the set-up mode and, if a said second signal is detected by at least one pair of first communications modules adapted to communicate directly with each other in the communication mode, causing said third communications module to be installed to communicate directly with said two first communications modules of at least one said pair in said communication mode .

This provides the advantage of enabling sub groups of the system to be formed which pass messages around a generally circular loop, in combination with being able to transmit messages along a generally linear chain covering large distances .

In a preferred embodiment, at least one said second or third communications module is programmed with an address identifying the or each module with which said module communicates directly when in said communication mode, and the step of causing said second or third communications module to be inserted into the system comprises updating the addresses of said modules adapted to transmit messages in the system subsequently to the communications module to be inserted.

The method may further comprise the step of testing reliability of communications links between the said second and or third communications module and those modules with which it is to communicate directly when in said communication mode.

In a preferred embodiment, the step of testing reliability comprises directly exchanging at least one message between said communications module to be inserted and those modules with which it is to communicate directly when in said communication mode .

The method may further comprise the step of changing the or each said second or third communications module from said setup mode to said communication mode by means of a signal from at least one said control module. A preferred embodiment of the invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which-.-

Figures 1 to 4 are a schematic illustration of a prior art process for automatically installing further communications modules into a wireless communica ion system;

Figure 5 illustrates a wireless communication system set up using a method embodying the present inventio ,-

Figure 6 is a schematic illustration of a wireless communication system corresponding to the system of figure 5 with a further communications module to be added; and

Figure 7 is a schematic illustration of addition of a further communications module to a central part of an existing linear wireless communication system.

Referring to figure 5, a wireless communication system is arranged in a generally linear chain and is initially set up by providing a control module 100 and a first communications module 101. The communications module 101 transmits a radio frequency wireless message to the control module 100, and the control module 100 has address number 0, and the communications module 101 is allocated address number 1, so that it communicates directly with the control module 100.

When a second communications module 102 is to be inserted into the system in the position shown in figure 5 (i.e. at the end of the chain remote from the control module 100) , the new module 102 is caused to emit a message in a set-up mode. Initially, the existing module 100,101 which received the message with the strongest signal intensity (module 101 in the case of figure 5, because of its proximity to the new module 102) is identified. The new module 102 is then caused to communicate directly with the existing module 101 by allocating address number 2 to the module 102.

Similarly, referring to figure 6, when a new module 103 is to be introduced into the system of figure 5, the new module 103 is caused to emit a message in a set-up mode. The message is received by existing module 102 (again because of its proximity) with the greatest signal strength. A determination is then made whether the message is received by any other modules. If the message is received by existing module 102 (i.e. the module receiving the signal with the greatest signal strength) and at least one other existing module 100 or 101, the new module 103 is incorporated into the system, and caused to communicate directly with existing module 102 by allocating address number 3 to the new module 103.

It will be appreciated by persons skilled in the art that the process of figure β can be extended to incorporate further new modules 104, 105 at the end of the chain as shown in figure 7. When a new module 106 is to be introduced at a central part of the chain, the new module 106 is caused, in the manner described above, to emit a signal in a set-up mode. The existing unit 103 which receives the message from unit 106 with the greatest signal strength (again, because of its proximity to the new unit 106) is identified. The new unit 106 is then caused to communicate directly with existing unit 103 when in the communication mode by allocating address number 4 to the new unit 106. However, because the new unit 106 is not located at the end of a generally linear chain with existing units 104, 105, the new unit 106 is either prevented from being installed in the system unless it can communicate directly with existing unit 104 (the unit which prior to insertion of module 106 communicated directly with module 103) , in which case the addresses of existing modules 104 and 105 are incremented to address numbers 5 and 6 respectively or, alternatively, the new module 106 and existing module 105 are allocated different sub addresses of the same hierarchy so that both modules 106, 104 communicate directly with existing module 103, and existing module 105 communicates directly with existing module 104 but not module 106.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only, and not in any limitative sense, that various alternations and modifications are possible without departure from the scope of the invention as defined by the appended claims.

Claims

CLAI S

1. A method of inserting a communications module into a wireless communications system comprising at least one control module and a plurality of first communications modules, wherein the system is adapted, when in a communication mode, to transmit wireless messages sequentially between modules, and wherein each said first communications module is adapted to receive a wireless message and transmit that message to a further first communications module or to a said control module, the method comprising-. -

(i) causing a second communica ions module, which is to be inserted into the system, to transmit at least one first message in a set-up mode;

(iii) causing said second communications module, when in said communication mode, to communicate directly with a first said communications module with received a said first message with the highest signal intensity.

2. A method according to claim 1, further comprising the step of only causing said second communications module to be installed in the system if a said first message is received by at least two said first communications modules.

3. A method according to claim 2, further comprising the step of only causing said second communications module to be installed in the system if a said first message is received by said first communications module which received the message with greatest signal strength and a further said first communications module adapted to communicate directly with said first communications module which received the signal with greatest signal strength.

4. A method according to any one of the preceding claims, further comprising the step of causing a third communications module, which is to be inserted into the system, to transmit at least one second message in the set-up mode and, if a said second signal is detected by at least one pair of first communications modules adapted to communicate directly with each other in the communication mode, causing said third communications module to be installed to communicate directly with said two first communications modules of at least one said pair in said communication mode.

5. A method according to claim 4, wherein at least one said second or third communications module is programmed with an address identifying the or each module with which said module communicates directly when in said communication mode, and the step of causing said second or third communications module to be inserted into the system comprises updating the addresses of said modules adapted to transmit messages in the system subsequently to the communications module to be inserted.

6. A method according to claim 4 or 5 , further comprising the step of testing reliability of communications links between the said second and or third communications module and those modules with which it is to communicate directly when in said communications mode.

7. A method according to claim 6 , wherein the step of testing reliability comprises directly exchanging at least one message between said communications module to be inserted and those modules with which it is to communicate directly when in said communication mode.

8. A method according to any one of claims 4 to 7, further comprising the step of changing the or each said second or third communications module from said set-up mode to said communications mode by means of a signal from at least one said control module .

9. A method of inserting a communications module into a wireless communications system comprising at least one control module and a plurality of first communications modules, wherein the system is adapted, when in a communication mode, to transmit wireless messages sequentially between modules, and wherein each said first communications module is adapted to receive a wireless message and transmit that message to a further first communications module or to a said control module, the method substantially as hereinbefore described with reference to figures 5 to 7 of the accompanying drawings .