CA2176666A1 - Processor-controlled facility for tracking a mobile station in an sdma mobile radio system - Google Patents
Processor-controlled facility for tracking a mobile station in an sdma mobile radio systemInfo
- Publication number
- CA2176666A1 CA2176666A1 CA002176666A CA2176666A CA2176666A1 CA 2176666 A1 CA2176666 A1 CA 2176666A1 CA 002176666 A CA002176666 A CA 002176666A CA 2176666 A CA2176666 A CA 2176666A CA 2176666 A1 CA2176666 A1 CA 2176666A1
- Authority
- CA
- Canada
- Prior art keywords
- ctr
- mobile station
- processor
- facility
- cell
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W64/00—Locating users or terminals or network equipment for network management purposes, e.g. mobility management
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
Processor-controlled facilities for tracking the mobile stations in an SDMA mobile radio system are known;
they continuously monitor a radio signal received from a base station, and determine the input direction (.alpha.) and the distance (r) between the base station (BTS) and a mobile station (MS) that transmits the radio signal. The monitoring of the radio signal serves also to support a hand-off of the mobile station (MS) from one cell (C) to the next one (C'). The invention improves such a processor-controlled facility (CTR), so that it determines by means of the signal monitoring whether the mobile station (MS) moves essentially along the boundary of cell (C), and that in such a case the facility sends a blocking signal (NOHO) to a device (BSC), which controls the hand-off and blocks it on the basis of the blocking signal. This prevents any useless back and forth hand-off of the mobile station.
they continuously monitor a radio signal received from a base station, and determine the input direction (.alpha.) and the distance (r) between the base station (BTS) and a mobile station (MS) that transmits the radio signal. The monitoring of the radio signal serves also to support a hand-off of the mobile station (MS) from one cell (C) to the next one (C'). The invention improves such a processor-controlled facility (CTR), so that it determines by means of the signal monitoring whether the mobile station (MS) moves essentially along the boundary of cell (C), and that in such a case the facility sends a blocking signal (NOHO) to a device (BSC), which controls the hand-off and blocks it on the basis of the blocking signal. This prevents any useless back and forth hand-off of the mobile station.
Description
. 21 76~
' --Field of the Tnvention The invention concern3 a processor-controlled facility which monitors a radio signal received by at least one base station in an SDMA mobile radio system, to track a mobile station which transmits this radio signal within a cell serviced by the base station. It is also directed to a base station which is equipped therewith, and a base station control for an SDMA (Space Division Multiple Access) mobile radio system.
Descri~tign o~ th~ Prior ~r~
Such a facility is known from Wo 93~12590. A
facility called an SDMA controller is described therein, which monitors a signal received by a base station, to track a mobile station which is located in a cell serYiced by the base station and transmits this radio signal. As described in WO 93/12590 on pages 22 to 24, to determine the present location of the mobile station, the direction of arrival DOA f rom which the radio signal is received, and the time of arrival TOA of the radio signal, are acquired. The SDMA controller continuously acquires these radio signal parameters, to alleviate problems during hand-off of the mobile station from one cell to the next one (see page 24, paragraph 1) . How the problems are alleviated is not described in detail by WO
93/12590. Nor does it describe a solution for the generally known problem with cellular radio systems, where control of the hand-of f can assume an unstable state, 80 that the mobile station must be handed off repeatedly back and forth between two cells.
S ,~ o~ the TnYention The task of the invention is to improve the facility described earlier, 80 as to support the control of the hand-off and aYoid this problem. The task is fulilled by a processor-controlled facility that by monitoring the radio signal determines whether the mobile 21 ~6~
. ~
station move3 essentially along the boundary of the cell, and in that case blocks tile hand-off of the mobile station by 3ending a blocking signal to a device in the SDMA mobile radio system, which controls the hand-of f .
Accordingly, the facility of the invention determines whether the mobile station moves essentially along the cell boundary, and in that case blocks the hand-of f of the mobile station by sending a blocking signal to a device of the SDMA mobile radio system, which controls the hand-off. This prevents the hand-off control from assuming an unstable state, which leads to increased si~nAll;n~ and thus loading of the controlling device, such as perhaps the radio switching center. The facility of the invention can be carried out simply by nfl;ng the monitoring of tile radio signal, which is required anyway. The device can be integrated into a base station or into a base station controller.
Descri~tion of the Drawinas The following describes a first and a second configuration example of the invention by means of the drawings, which schematically illustrate the construction of an SDMA mobile radio system, where:
Figure 1 depicts how the device of the invention is integrated into a base station, and Figure 2 depicts how the device of the invention is integrated into a base station controller.
In addition, figure 1 represents a situation in which the device blocks a hand-off. In contrast, figure
' --Field of the Tnvention The invention concern3 a processor-controlled facility which monitors a radio signal received by at least one base station in an SDMA mobile radio system, to track a mobile station which transmits this radio signal within a cell serviced by the base station. It is also directed to a base station which is equipped therewith, and a base station control for an SDMA (Space Division Multiple Access) mobile radio system.
Descri~tign o~ th~ Prior ~r~
Such a facility is known from Wo 93~12590. A
facility called an SDMA controller is described therein, which monitors a signal received by a base station, to track a mobile station which is located in a cell serYiced by the base station and transmits this radio signal. As described in WO 93/12590 on pages 22 to 24, to determine the present location of the mobile station, the direction of arrival DOA f rom which the radio signal is received, and the time of arrival TOA of the radio signal, are acquired. The SDMA controller continuously acquires these radio signal parameters, to alleviate problems during hand-off of the mobile station from one cell to the next one (see page 24, paragraph 1) . How the problems are alleviated is not described in detail by WO
93/12590. Nor does it describe a solution for the generally known problem with cellular radio systems, where control of the hand-of f can assume an unstable state, 80 that the mobile station must be handed off repeatedly back and forth between two cells.
S ,~ o~ the TnYention The task of the invention is to improve the facility described earlier, 80 as to support the control of the hand-off and aYoid this problem. The task is fulilled by a processor-controlled facility that by monitoring the radio signal determines whether the mobile 21 ~6~
. ~
station move3 essentially along the boundary of the cell, and in that case blocks tile hand-off of the mobile station by 3ending a blocking signal to a device in the SDMA mobile radio system, which controls the hand-of f .
Accordingly, the facility of the invention determines whether the mobile station moves essentially along the cell boundary, and in that case blocks the hand-of f of the mobile station by sending a blocking signal to a device of the SDMA mobile radio system, which controls the hand-off. This prevents the hand-off control from assuming an unstable state, which leads to increased si~nAll;n~ and thus loading of the controlling device, such as perhaps the radio switching center. The facility of the invention can be carried out simply by nfl;ng the monitoring of tile radio signal, which is required anyway. The device can be integrated into a base station or into a base station controller.
Descri~tion of the Drawinas The following describes a first and a second configuration example of the invention by means of the drawings, which schematically illustrate the construction of an SDMA mobile radio system, where:
Figure 1 depicts how the device of the invention is integrated into a base station, and Figure 2 depicts how the device of the invention is integrated into a base station controller.
In addition, figure 1 represents a situation in which the device blocks a hand-off. In contrast, figure
2 represents a situation in which the device releases an early hand-of f .
Det~;led Descri~tion of the Preferred ~ l;
The SDMA mobile radio system, which is schematically illustrated in figure 1, comprises base stations BTS and BTS', each of which services a cell C or ~1 ~6~ ~
C'. The base stations are connected to a baae station controller sSC, which in turn is connected to a mobile switching center MSC. The mobile switching center MSC, which cnn~;n~ a data bank, as well as the base station controller BSC, control the mobile station MS hand-off from one cell to the next one. In this example, the mobile station MS is radio-connected to the base station BTS, which services the cell C. To perform an SDMA radio transmission, the base station BTS i8 equipped with a phase-controlled group antenna and with a radio transmitter-receiver TRX, such as is known perhaps from ,Wo 93/12590. Beyond that, the base station BTS comprises a processor-controlled facility CTR which is connected to the transmitter-recelver TRX and which, in accordance with the invention, monitors a radio signal it receives from it, to determine whether the mobile station that transmits the radio signal is moving along the boundary of cell C. In that case, the facility CTR sends a blocking signal NOHO to the base station controller BSC, to prevent a hand-off of the mobile station MS to one of the neighboring cells, such as perhaps cell C'.
During the radio transmission between the mobile station MS and the base 3tation BTS, the facility rnn~ i nllr,ugly acr1uire8 the signal transfer time of the radio signal in the upward channel, at predetermined intervals of about 30 seconds. To that end, the base station BTS sends a f irst radio pulse to the mobile station MS. After it receives the radio pulse, the latter waits for a predetermined time interval dT, which is about 1. 7 ms long, and sends a second radio pulse in response to the base station BTS. The facility CTR now determines the l3ignal transfer time Tp in accordance with the following equation: Tp = 0.5 x (Tsum - dT), where Tsum is the time interval measured by the facility CTR
between the transmission of the first radio pulse and the reception of the second radio pulse. The continuously determined values of the signal transfer time are entered 21 766~6 . ~
into the data bank DB. The facility calculates changes in the signal transfer time by comparing the value determined last with the values determined previously.
If the changes are within a tolerance range of about 1 ~18, it is assumed that the distance r between the moblle station MS and the base station BTS has not changed significantly (1 ~L8 corresponds to about 300 m). By monitoring the input direction a, from which the radio signal is received by the base station BTS, the facility CTR then determines that the mobile station MS is moving vertically to the radius of cell C. To determine whether -=
the mobile station is moving along the boundary of cell C, the facility CTR evaluates the last-determined amount o~ the radio signal~s transfer time. If the determined 3ignal transfer time is about 50 ~8, the mobile station MS is located at the boundary of cell C, which in this instance has a diameter of about 30 km.
The facility then sends the blocking signal NOi~o to the device that controls the hand-off of mobile station MS, i.e. in this example to the base station controller BSC. Thi~ action interrupts any hand-off of the mobile station MS, as long as it is still located in the boundary area of cell C. In this way any multiple hand-off, during which the radio connection is switched back and forth within a chort period of time, is avoided.
Loading the signalling path3 in the mobile radio sy3tem i3 al30 avoided in this manner. Thus, the facility of the invention evaluates the radio signal parameter3 r and a, which are required anyway to carry out the SDMA radio transmission. This allow3 a very simple realization o~
the invention. As an alternative to the above-de~3cribed rm~nRtion of the signal transfer time, continuous monitoring of the input level can be performed to determine changes in the distance r. It can ~urthermore be envisioned to acquire both the signal transfer time and the input level, in order to monitor the distance reliably.
The above-described method of tracking a mobile station MS can be applied to any mobile station moving within the SDMA mobile radio 3ystem. It is then an advantage to link the acquired radio signal parameters such aa input direction, input level or 3ignal transfer time, to time indications, which indicate the time of the ac~uisition. All data are atored in the data bank DB and constitute the records of a data file, which can be accessed during resource planning or redistribution.
These records can be used to derive motion profiles, which indicate at what times ~weekday3, clock-times) and how the subscriber density is distributed in the radio network. To better utilize the radio resources, it is sufficient to perform such a statistical data acquisition separately and independently of the proposed radio signal monitoring and the hand-off blocking.
A second configuration example will now be described by means of f igure 2, which schematically illustrates an SDMA mobile radio system that only differs from the SDMA mobile radio system as follows:
In this second configuration example, the processor-controlled facility CTR is integrated into the base station controller sSC and not into base stations BTSl and BTS2. This results in the monitoring of the received signals, i . e . the monitoring of the upward radio channels, in a central area of the mobile radio system.
In this example, the central area is the base station controller BSC, which controls the radio channel assignment and the hand-off in this assigned area, the so-called BSC area. In this way the invention improves the conventional radio signal monitoring required anyway, in order to prevent any unnecessary hand-of f .
The situation depicted schematically in figure 2 shows a moving mobile station MS, which leaves the cell C1 in the direction of the neighboring cell C2. By monitoring the radio signal received from the base station BTS1 in accordance with the invention, the processor-controlled facility CTR determines that the =-mobile station MS i8 moving toward the boundary o~ cell Cl. By evaluating the motion profile data r (t) and ~
(t) stored in the data bank, the facility CTR determines the present position, the principal direction of movement and the average speed of the mobile station MS. The facility CTR then calculates a point in time at which the mobile station MS will reach the cell boundary. At that point in time, which can also be defined by an input level threshold value, the hand-off of the mobile station MS can be released in the conventional manner.
~ lowever, before reaching this point in time, the facility CTR of the invention sends a release aignal H0 to the device which controls the hand-off. In the example of figure 2, the facility CTR sends the determined direction of movement ~Y as the release signal E~O to the mobile switching center MSC, which in this case controls the hand-o~f. The calculation of the actual direction of I ,v -nt of mobile station MS is omitted in that example, i.e. a calculation baaed on the determined signal transfer times and/or the input levels, by equating the direction of movement to the input direction of the radio signal. This 3implification is permitted when the cell radius (in this instance e.g. 15 km) is large by comparison with the last determined distance of the mobile station MS from the cell boundary (e.g. 1 km in thia case). Tn this way, the facility CTR illustrated in figure 2 continuously evaluates the signal transfer time and the complex weighting factors of the radio signal received from the base station sTS1, to obtain two time functions which indicate changes in the distance r (t) and changes in the input direction cY (t). These two time functions characterize the motion profile of the mobile station MS, and are sufficient to determine in which direction the mobile station MS is leaving the cell C1, and to release an early hand-off to the closest cell C2 in that direction. The continuous evaluation of the signal transfer time and that of the weighting factors takes place at predetermined time intervals, which decrease as the acquired signal transfer time increases.
In this case, time intervals of about 2 min., 1 min. or 30 sec. are determined for a signal transfer time of about 10 IL8, 20 ~L8, or 50 1l8. This measure allows the facility CTR to perform the evaluation of the invention in short time intervals only if the mobile station MS is located in the core area of a ccll. If the mobile lo station MS is located in the core area of the cell (short signal transfer time), slow monitoring (long time intervals) is sufficient. In this way, the calculation effort of the processor-controlled facility CTR can be reduced. In this example, the processor-controlled facility CTR is conatructed on the basis of the control electronics in the base station controller BSC, which are required anyway. It can also be envisioned to implement the facility by means of a personal computer, which is connected to the data bank.
The invention described with the two conf iguration examples can also be implemented Wit~l other imaginable variations. Thus, the processor-controlled facility could also be integrated into a radio switching center, particularly in con~unction with the data bank.
Det~;led Descri~tion of the Preferred ~ l;
The SDMA mobile radio system, which is schematically illustrated in figure 1, comprises base stations BTS and BTS', each of which services a cell C or ~1 ~6~ ~
C'. The base stations are connected to a baae station controller sSC, which in turn is connected to a mobile switching center MSC. The mobile switching center MSC, which cnn~;n~ a data bank, as well as the base station controller BSC, control the mobile station MS hand-off from one cell to the next one. In this example, the mobile station MS is radio-connected to the base station BTS, which services the cell C. To perform an SDMA radio transmission, the base station BTS i8 equipped with a phase-controlled group antenna and with a radio transmitter-receiver TRX, such as is known perhaps from ,Wo 93/12590. Beyond that, the base station BTS comprises a processor-controlled facility CTR which is connected to the transmitter-recelver TRX and which, in accordance with the invention, monitors a radio signal it receives from it, to determine whether the mobile station that transmits the radio signal is moving along the boundary of cell C. In that case, the facility CTR sends a blocking signal NOHO to the base station controller BSC, to prevent a hand-off of the mobile station MS to one of the neighboring cells, such as perhaps cell C'.
During the radio transmission between the mobile station MS and the base 3tation BTS, the facility rnn~ i nllr,ugly acr1uire8 the signal transfer time of the radio signal in the upward channel, at predetermined intervals of about 30 seconds. To that end, the base station BTS sends a f irst radio pulse to the mobile station MS. After it receives the radio pulse, the latter waits for a predetermined time interval dT, which is about 1. 7 ms long, and sends a second radio pulse in response to the base station BTS. The facility CTR now determines the l3ignal transfer time Tp in accordance with the following equation: Tp = 0.5 x (Tsum - dT), where Tsum is the time interval measured by the facility CTR
between the transmission of the first radio pulse and the reception of the second radio pulse. The continuously determined values of the signal transfer time are entered 21 766~6 . ~
into the data bank DB. The facility calculates changes in the signal transfer time by comparing the value determined last with the values determined previously.
If the changes are within a tolerance range of about 1 ~18, it is assumed that the distance r between the moblle station MS and the base station BTS has not changed significantly (1 ~L8 corresponds to about 300 m). By monitoring the input direction a, from which the radio signal is received by the base station BTS, the facility CTR then determines that the mobile station MS is moving vertically to the radius of cell C. To determine whether -=
the mobile station is moving along the boundary of cell C, the facility CTR evaluates the last-determined amount o~ the radio signal~s transfer time. If the determined 3ignal transfer time is about 50 ~8, the mobile station MS is located at the boundary of cell C, which in this instance has a diameter of about 30 km.
The facility then sends the blocking signal NOi~o to the device that controls the hand-off of mobile station MS, i.e. in this example to the base station controller BSC. Thi~ action interrupts any hand-off of the mobile station MS, as long as it is still located in the boundary area of cell C. In this way any multiple hand-off, during which the radio connection is switched back and forth within a chort period of time, is avoided.
Loading the signalling path3 in the mobile radio sy3tem i3 al30 avoided in this manner. Thus, the facility of the invention evaluates the radio signal parameter3 r and a, which are required anyway to carry out the SDMA radio transmission. This allow3 a very simple realization o~
the invention. As an alternative to the above-de~3cribed rm~nRtion of the signal transfer time, continuous monitoring of the input level can be performed to determine changes in the distance r. It can ~urthermore be envisioned to acquire both the signal transfer time and the input level, in order to monitor the distance reliably.
The above-described method of tracking a mobile station MS can be applied to any mobile station moving within the SDMA mobile radio 3ystem. It is then an advantage to link the acquired radio signal parameters such aa input direction, input level or 3ignal transfer time, to time indications, which indicate the time of the ac~uisition. All data are atored in the data bank DB and constitute the records of a data file, which can be accessed during resource planning or redistribution.
These records can be used to derive motion profiles, which indicate at what times ~weekday3, clock-times) and how the subscriber density is distributed in the radio network. To better utilize the radio resources, it is sufficient to perform such a statistical data acquisition separately and independently of the proposed radio signal monitoring and the hand-off blocking.
A second configuration example will now be described by means of f igure 2, which schematically illustrates an SDMA mobile radio system that only differs from the SDMA mobile radio system as follows:
In this second configuration example, the processor-controlled facility CTR is integrated into the base station controller sSC and not into base stations BTSl and BTS2. This results in the monitoring of the received signals, i . e . the monitoring of the upward radio channels, in a central area of the mobile radio system.
In this example, the central area is the base station controller BSC, which controls the radio channel assignment and the hand-off in this assigned area, the so-called BSC area. In this way the invention improves the conventional radio signal monitoring required anyway, in order to prevent any unnecessary hand-of f .
The situation depicted schematically in figure 2 shows a moving mobile station MS, which leaves the cell C1 in the direction of the neighboring cell C2. By monitoring the radio signal received from the base station BTS1 in accordance with the invention, the processor-controlled facility CTR determines that the =-mobile station MS i8 moving toward the boundary o~ cell Cl. By evaluating the motion profile data r (t) and ~
(t) stored in the data bank, the facility CTR determines the present position, the principal direction of movement and the average speed of the mobile station MS. The facility CTR then calculates a point in time at which the mobile station MS will reach the cell boundary. At that point in time, which can also be defined by an input level threshold value, the hand-off of the mobile station MS can be released in the conventional manner.
~ lowever, before reaching this point in time, the facility CTR of the invention sends a release aignal H0 to the device which controls the hand-off. In the example of figure 2, the facility CTR sends the determined direction of movement ~Y as the release signal E~O to the mobile switching center MSC, which in this case controls the hand-o~f. The calculation of the actual direction of I ,v -nt of mobile station MS is omitted in that example, i.e. a calculation baaed on the determined signal transfer times and/or the input levels, by equating the direction of movement to the input direction of the radio signal. This 3implification is permitted when the cell radius (in this instance e.g. 15 km) is large by comparison with the last determined distance of the mobile station MS from the cell boundary (e.g. 1 km in thia case). Tn this way, the facility CTR illustrated in figure 2 continuously evaluates the signal transfer time and the complex weighting factors of the radio signal received from the base station sTS1, to obtain two time functions which indicate changes in the distance r (t) and changes in the input direction cY (t). These two time functions characterize the motion profile of the mobile station MS, and are sufficient to determine in which direction the mobile station MS is leaving the cell C1, and to release an early hand-off to the closest cell C2 in that direction. The continuous evaluation of the signal transfer time and that of the weighting factors takes place at predetermined time intervals, which decrease as the acquired signal transfer time increases.
In this case, time intervals of about 2 min., 1 min. or 30 sec. are determined for a signal transfer time of about 10 IL8, 20 ~L8, or 50 1l8. This measure allows the facility CTR to perform the evaluation of the invention in short time intervals only if the mobile station MS is located in the core area of a ccll. If the mobile lo station MS is located in the core area of the cell (short signal transfer time), slow monitoring (long time intervals) is sufficient. In this way, the calculation effort of the processor-controlled facility CTR can be reduced. In this example, the processor-controlled facility CTR is conatructed on the basis of the control electronics in the base station controller BSC, which are required anyway. It can also be envisioned to implement the facility by means of a personal computer, which is connected to the data bank.
The invention described with the two conf iguration examples can also be implemented Wit~l other imaginable variations. Thus, the processor-controlled facility could also be integrated into a radio switching center, particularly in con~unction with the data bank.
Claims (7)
1. A processor-controlled facility (CTR) which monitors a radio signal received by at least one base station (BTS) in an SDMA mobile radio system, to track a mobile station (MS) which transmits this radio signal within a cell (C) serviced by the base station (BTS), characterized in that by monitoring the radio signal, the processor-controlled facility (CTR) determines whether the mobile station (MS) moves essentially along the boundary of the cell (C), and in that case blocks the hand-off of the mobile station (MS) by sending a blocking signal (NOHO) to a device (MSC) in the SDMA mobile radio system, which controls the hand-off.
2. A processor-controlled facility (CTR) as claimed in claim 1, characterized in that the facility (CTR) monitors the radio signal by means of the continuous acquisition of its input level and/or its signal transfer time.
3. A processor-controlled facility (CTR) as claimed in claim 2, characterized in that the facility (CTR) can be connected to a data bank (DB), wherein it deposits the acquired input level and/or the signal transfer time, together with a time indication that contains the present clock-time.
4. A processor-controlled facility (CTR) as claimed in claim 1, characterized in that by monitoring the radio signal, the facility (CTR) determines whether the mobile station (MS) is essentially moving toward the boundary of the cell (C), and in that case determines the direction of the movement (.alpha.) and signals this movement to the device (MSC) which controls the hand-off, to release the mobile station (MS) hand-off in the direction of the nearest cell.
5. A processor-controlled facility (CTR) as claimed in claim 2, characterized in that the facility (CTR) acquires the radio signal transfer time at predetermined time intervals, and shortens the time intervals if the signal transfer time increases.
6. A base station (BTS) for an SDMA mobile radio system with a processor-controlled facility (CTR), which monitors a radio signal received by the base station (BTS) for tracking a mobile station (MS), which transmits this radio signal within a cell (C) that is serviced by the base station (BTS), characterized in that by monitoring the radio signal, the processor-controlled facility (CTR) determines whether the mobile station (MS) moves essentially along the boundary of the cell (C), and in such a case blocks a hand-off of the mobile station (MS) to a neighboring cell, by sending a blocking signal (NOHO) to a device (MSC) of the SDMA mobile radio system, which controls this hand-off.
7. A base station controller (BSC) for at least two base stations (BTS1, BTS2) within an SDMA mobile radio system, with a processor-controlled facility (CTR), which for each base station (BTS1) monitors a radio signal received by that station, for tracking a mobile station (MS) which transmits this radio signal within a cell (C1) serviced by the base station (BTS1), characterized in that by monitoring the radio signal, the processor-controlled facility (CTR) determines whether the mobile station (MS) moves essentially along the boundary of the cell (C), and in such a case blocks any further hand-off of the mobile station (MS), which is controlled by the base station controller (BSC), to a neighboring cell (C2), or sends a blocking signal to another device (MSC) of the SDMA mobile radio system, which controls the hand-off.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE1995118399 DE19518399A1 (en) | 1995-05-19 | 1995-05-19 | Processor-controlled device for tracking a mobile station in an SDMA mobile radio system |
| DE19518399.1 | 1995-05-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2176666A1 true CA2176666A1 (en) | 1996-11-20 |
Family
ID=7762341
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002176666A Abandoned CA2176666A1 (en) | 1995-05-19 | 1996-05-15 | Processor-controlled facility for tracking a mobile station in an sdma mobile radio system |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0743802A3 (en) |
| JP (1) | JPH08331627A (en) |
| CN (1) | CN1138283A (en) |
| AU (1) | AU698759B2 (en) |
| CA (1) | CA2176666A1 (en) |
| DE (1) | DE19518399A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3001570B1 (en) | 1999-02-22 | 2000-01-24 | 埼玉日本電気株式会社 | Adaptive antenna directivity control method and system |
| US6681099B1 (en) | 2000-05-15 | 2004-01-20 | Nokia Networks Oy | Method to calculate true round trip propagation delay and user equipment location in WCDMA/UTRAN |
| DE10238796B4 (en) * | 2002-08-23 | 2006-09-14 | Siemens Ag | Method for determining the position of a mobile station relative to a base station, mobile radio system and direction determination device |
| US20040203910A1 (en) * | 2002-12-31 | 2004-10-14 | International Business Machines Corporation | Spatial boundary admission control for wireless networks |
| EP1740000A1 (en) * | 2005-06-27 | 2007-01-03 | Siemens Aktiengesellschaft | Method for handover of a radio transmission by transmission power control of the base stations |
| CN101873650B (en) * | 2009-04-24 | 2012-11-14 | 大唐移动通信设备有限公司 | Switching method and device of user equipment in spatial division multiple access |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4475010A (en) * | 1983-05-05 | 1984-10-02 | At&T Bell Laboratories | High density cellular mobile radio communications |
| US4654879A (en) * | 1985-03-29 | 1987-03-31 | Itt Corporation | Cellular mobile radio subscriber location detection |
| EP0210396B1 (en) * | 1985-08-02 | 1992-05-13 | ANT Nachrichtentechnik GmbH | Method for determining the position of mobile stations |
| DE3716320A1 (en) * | 1987-05-15 | 1988-11-24 | Bosch Gmbh Robert | METHOD FOR DETERMINING THE APPROXIMATE LOCATION OF A MOBILE RADIO STATION |
| US5170485A (en) * | 1990-11-07 | 1992-12-08 | Motorola, Inc. | Hand-off algorithm for elongated radiotelephone cells |
| US5515378A (en) * | 1991-12-12 | 1996-05-07 | Arraycomm, Inc. | Spatial division multiple access wireless communication systems |
| DE59309086D1 (en) * | 1992-08-26 | 1998-11-26 | Siemens Ag | MOBILE RADIO NETWORK |
| US5327144A (en) * | 1993-05-07 | 1994-07-05 | Associated Rt, Inc. | Cellular telephone location system |
-
1995
- 1995-05-19 DE DE1995118399 patent/DE19518399A1/en not_active Withdrawn
-
1996
- 1996-05-08 EP EP96107226A patent/EP0743802A3/en not_active Withdrawn
- 1996-05-09 AU AU52171/96A patent/AU698759B2/en not_active Ceased
- 1996-05-15 CA CA002176666A patent/CA2176666A1/en not_active Abandoned
- 1996-05-17 CN CN 96100287 patent/CN1138283A/en active Pending
- 1996-05-20 JP JP12515696A patent/JPH08331627A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP0743802A3 (en) | 1999-05-19 |
| DE19518399A1 (en) | 1996-11-21 |
| JPH08331627A (en) | 1996-12-13 |
| AU5217196A (en) | 1996-11-28 |
| EP0743802A2 (en) | 1996-11-20 |
| CN1138283A (en) | 1996-12-18 |
| AU698759B2 (en) | 1998-11-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 20030515 |