GB2324440A

GB2324440A - Monitoring the operational status of cellular communication regions

Info

Publication number: GB2324440A
Application number: GB9706962A
Authority: GB
Inventors: John Mathews; Gavin Simpson; Tim Charity
Original assignee: Motorola Ltd
Current assignee: Motorola Solutions UK Ltd
Priority date: 1997-04-05
Filing date: 1997-04-05
Publication date: 1998-10-21
Anticipated expiration: 2017-04-05
Also published as: CN1200005A; FR2762469A1; GB9706962D0; DE19815392B4; GB2324440B; DE19815392A1; FR2762469B1; CN1107432C

Abstract

A system for monitoring the operational status of a region of a cellular radio communication system, comprising means for receiving data signals indicative of changes in the operational status of specified operational units within a given region of the cellular radio communication system, means for storing the data signals, a central processing unit adapted to sense when a data signal is entered into the data signal store, determine from the stored data signals the number of the said units in a given operational state, compare the number of the said units in the given operational state with the known total number of units of the same type as the specified type in the given region of the cellular radio communication system and produce an operational status signal related to a mathematical relationship therebetween, a store adapted to receive the operational status signal and means for producing a visual representation of the operational status signal.

Description

2324440 RF Carrier Availability Monitor

Field of the Invention

CE30280P The present invention relates to the management of cellular radio communication systems and, more specifically to cellular radio communication systems which conform with the specifications devised by the body known as Global System for Mobile Communications (GSM Systems).

Backaround of the Invention

Cellular radio communication systems have an hierarchical structure. A given geographical region within such a system is divided initially into areas, known in GSM Systems, as base station- systems. These are divided into smaller regions served by transceiver stations known as base transceiver stations, which again are divided into cells which contain one or more radio frequency transceiver units which operate at different carrier frequencies and are the units which actually communicate with mobile transceiver units within their respective cell. The base stationsystems are linked to mobile switching centres and thence to other base station-systems within the cellular radio communication system. A consequence of this hierarchical structure is that if one of the higher levels suffers an operational failure, then effectively, the levels below and linked to it also are rendered unserviceable unless some alternative or back-up system can be brought into service.

2 Summarv of the Invention It is an object of the present invention to provide a system for monitoring the operational state of a cellular radio communication system to facilitate the most effective use of its resources.

According to the present invention there is provided a system for monitoring the operational status of a region of a cellular radio communication system, comprising means for receiving data signals indicative of changes in the operational status of specified operational units within a given region of the cellular radio communication system, means for storing the data signals, a central processing unit adapted to sense when a data signal is entered into the data signal store, determine from the stored data signals the number of the said units in a given operational state, compare the number of the said units in the given operational state with the known total number of units of the same type as the specified type in the given region of the cellular radio communication system and produce an operational status signal related to a mathematical relationship therebetween, a store adapted to receive the operational status signal and means for producing a visual representation of the operational status signal.

3 The data signals are adapted to identify the type and location of the specified operational units within the region of the cellular radio communication system.

The operational status signals preferably are indicative of the percentage of the said units which are in an operational state.

The visual representation of the operational status signal preferably is in the form of a bar the length of which is indicative of the percentage of the said units which are in an operational state, and preferably the operational status signals of more than one group of units at the same level in the hierarchy of operational units which constitute the cellular radio communication system are displayed simultaneously as an array of parallel bars having the same metric.

Preferably the visual representation of the operational status signal is colour coded to indicate when the proportion of operational units in a given level in the hierarchy of operational units which constitutes the specified region of the cellular radio communication system in a given operational state lies within specified limits.

Preferably, the visual representation of the operational status signal is displayed on the screen of a visual display unit in the form of a vertical array of horizontal bars. Each bar represents the units of a particular hierarchical level in a 4 specified region of the cellular radio communication system and the length of each bar represents the percentage of those units which are operational, or non-operational, as preferred.

Preferably there is included a facility for displaying the operational status of more than one level of the hierarchy simultaneously.

Brief Descri-otion of the DrawinGLa The invention will now be described and explained, by way of example, with reference to the accompanying drawings in which, FIG. 1 is a diagrammatic representation of the hierarchy of units in a cellular radio communication system of the GSM type.

FIG. 2 is a diagranunatic representation of an embodiment of the invention.

FIG. 3 shows a display representative of the operational status of units at one level in the hierarchy of units forming a cellular radio communication system produced by means of the invention, and FIG. 4 shows a similar display representative of the operational status of units in a different level of the hierarchy of units forming a cellular radio communication system produced by means of the invention.

Referring to FIG. 1, a region 1 of a GSM-type cellular radio communication system is divided into base station systems.(BSSs) 2, of which only two are shown. The base station systems 2 are divided into base transceiver stations (BTSs) 3, of which four are shown. Each of the base transceiver stations 3 is divided into one or more cells 4, each of which contains at least one radio frequency (RF) carrier 5.

Each of the radio frequency carriers 5 consists of a transceiver having two components, a digital radio interface (DRI) and a signal processor known as a receive/transmit function (RTF) both of which must be operational for the radio frequency carrier to function. Each radio frequency carrier operates at a different, specifically assigned, frequency and is the unit which actually communicates with a linked mobile transceiver unit situated within its associated cell 4.

Each of the units of the above system is adapted to produce signals, or event messages, relating to its identity and operational state, which are relayed to an operations and maintenance centre 6.

The internal arrangements within the operations and maintenance centre 6 are shown in FIG. 2. Referring to FIG. 2, the operations and maintenance centre 6 includes a data input register 21 to which the event messages from all the units within the region 1 of the cellular radio communication systems are applied. The event messages are sorted into 6 categories according to the level of unit and locality from which they are received and are stored temporarily in a store 22. Connected to the store 22 is a central processing unit 23 which is arranged to sense each time an event message is received at the operations management centre 6 and added to those in the store 22, interrogate the store 22, extract the stored event messages relating to each level of units of the cellular radio communication system, compare the number of stored event messages relating to a given level of units with the known number of units of that level in the region 1 of the cellular radio communication system, produce an operational status signal related thereto, which also includes components which identify the region 1 of the cellular radio communication system concerned, and store the amended data. At the behest of an operations manager 7 the current data are extracted from the store in the central processing unit 23 and displayed on the screen of a visual display unit 24 in the form of a vertical array of horizontal bars, the length of each of which corresponds to the proportion of units at a given level in the hierarchy of units contained at locations within the region of the cellular radio co=unication system which are operational, or non-operational if preferred, as shown in FIG.3 and FIG. 4. To facilitate the operation of the monitoring system, the bars are colour-coded to indicate that the proportion of units in a given operational state lies within specified limits. For example, when the proportion of units in service is greater than 90%, the bars could be coloured green, when the proportion of units in 7 service is between 80% and 90%, the bars could be coloured yellow and when the proportion of units in service is less than 80%, the bars could be coloured red.

FIG. 3 shows a display relating to both components of the radio-frequency carriers of cells and FIG. 4 shows a display relating to base station systems in the region 1 of the cellular radio 10 communication systems.

The central processing unit 23 operates on a model that a) if a base station system goes out of service, then all the base transceiver sites within it also are out of service b) if a component of a base station system goes out of service, then those base transceiver stations which are dependent on those components of the base station system also are out of service c) if a base transceiver site goes out of service, then all its associated cells are out of service, and d) if a cell goes out of service, then all its 30 radio frequency carriers (that is, the combination of digital radio interfaces and 8 receive transmit functions) also are out of service.

The percentage radio frequency carrier availability at each level of the hierarchy is given by the equations % RF carrier availability within a cell _ [min[(E(RTFins),1 X100 imn[(E(RTF),1 % RF carrier availability within a BTS mlln [min (Z (RMns (DRfins)) eel In I [min (I (RTFj (DR[))] cell I X100 % RF carrier availability within a BSS 1 BTSn(cel In = 1 1 [min (E (RTFins) 1 (DR1ins))]) BTSr(cWln Y. 1 [min (E (R TF (DRI) 1 BM Ceill A) 1 X100 In the above equations the sign 1 does not mean that the number of the units concerned are summed in a 9 strict mathematical sense but denotes the total number of the respective units. Also, the suffix ins denotes units in service.

Also, the term min is used to denote the operative pairs of digital radio interfaces and receive transmit functions, that is spare, or standby units are not included.

Also, unlike a conventional vulgar fraction, if the denominator of any of the above expressions is zero then the percentage availability of RF carriers associated with that expression is zero.

The form of display described is the most convenient, but other forms of display can be used. For example, a histogram or pie chart format could be used. Also the event messages can be generated in respect to units being restored to an operational state as well as in response to units going out of service.

In use, the operations manager 7 initially checks the indicated operational status of the base station systems. If the failure of a predetermined proportion of these is indicated, the operating manager 7 cheeks the indicated operational status of the base transceiver stations to determine where the failure of a proportion of the base transceiver stations is indicated and then the indicated operational status of the cells associated with each of the indicated failed base transceiver to determine where these have failed. If no higher level units are out of service, then there is no need to check the operational status of the lower level units because by virtue of the above algorithm, they must all be 5 operational.

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Claims

1. A system for monitoring the operational status of a region of a cellular radio communication system, comprising means for receiving data signals indicative of changes in the operational status of specified operational units within a given region of the cellular radio communication system, means for storing the data signals, a central processing unit adapted to sense when a data signal is entered into the data signal store, deter- mine from the stored data signals the number of the said units in a given operational state, compare the number of the said units in the given operational state with the known total number of units of the same type as the specified type in the given region of the cellular radio conununication system and produce an operational status signal related to a mathematical relationship therebetween, a store adapted to receive the operational status signal and means for producing a visual representation of the operational status signal.

2. A system according to Claim 1 wherein the data signals are adapted to identify the type and location of the specified operational units within the region of the cellular radio communication system.

3. A system according to Claim 1 or Claim 2 wherein the operational status signals are indicative of the proportion of the said operational units which are in an operational state.

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4. A system according to any preceding claim wherein the visual representation of the operational status signal for any given operational unit is in the form of a bar the length of which is a representation of the percentage of the given operational units which are in an operational state.

5. A system according to Claim 4 wherein the operational status signals relating to a plurality of groups of operational units at the same level in the hierarchy of operational units which constitute the region of the cellular radio communication systems are displayed simultaneously as an array of parallel bars having the same metric.

6. A system according to any preceding claim wherein the visual representation of the operational status signal for each level in the hierarchy of operational units which constitute the cellular radio communication system is colour coded to indicate when the proportion of those units in a given operational state lies within specified limits.

7. A system according to any preceding claim wherein the operational status signals for more than one hierarchical level of operational units can be displayed simultaneously.

8. A system according to Claim 7 wherein the display 30 of the operational status signals relating to a higher level of operational units includes a display of the operational status signal for subordinate levels of 13 operational units contained within the higher level of operational units.

9. A system according to any preceding claim wherein the displayed operational status signals are adapted to indicate the percentage of radio frequency carriers which are operational.

10. A system according to Claim 9 wherein the display is adapted to show the percentage of each component of a radio frequency carrier which is operational.

11. A system for monitoring the operational status of a region of a cellular radio connunication system substantially as hereinbefore described and with reference to the accompanying drawings.