KR20010099858A - Radiocommunication test system with internet protocol addressed clusters - Google Patents

Abstract

Test systems have been described for testing the stationary and mobile parts of a wireless telecommunications system. The moving part can be represented by a cluster of moving units in the IP-addressable housing. The housing can be connected to a computer workstation using an IP-compliant network, such as a LAN or a wireless IP network. In an exemplary embodiment of the present invention, ten mobile stations are removably disposed in a cradle mounted in an IP-addressable housing. Each mobile station can be connected to a separate portion of the IP server in the housing. Also, a power source may be included.

Description

RADIOCOMMUNICATION TEST SYSTEM WITH INTERNET PROTOCOL ADDRESSED CLUSTERS

The present invention relates generally to wireless telecommunications systems, and more particularly to a system for testing an air interface of a wireless telecommunications system.

In cellular telecommunications systems, a mobile switching center (MSC) is connected to the base station's network by a series of digital transmission links. Base stations are geographically dispersed to form the coverage area of the system. Each base station is designated to cover a specific area known as a cell, where bidirectional wireless communication may occur between the mobile station and the base station in the cell concerned. Mobile stations operating within a cell communicate with a base station over an air interface on a particular wireless channel.

The makers of wireless telecommunications devices have long recognized the importance of testing them before they are installed on site. Many tests run on base station equipment and mobile switching centers (MSCs) have typically been satisfactory and have resulted in the simulation of real-time conditions. Other areas, including the air interface, typically cannot be rigorously tested due to the inherent arbitrary environmental factors associated with the radio path, resulting in a lack of repeatability of the test process. For example, the actual environment in which the service provider operates may include factors that are difficult to rebuild in the test environment, such as variations in weather conditions, signal normals, log normals and multipaths that disappear due to barriers and / or terrain. Precise conditions can sometimes be difficult to return from the lab and recreate on a production site.

Another complex factor is the limited amount and type of tests that can be performed in the facility area without significant impact on current services. Since environmental conditions in the operating area cannot be guaranteed to continue to match, it can be difficult to be fully certain of the results from repeated tests. Therefore, it is difficult to prove the system reliability of the control software from repeated tests when the conditions need to be kept constant.

In conventional testing methods, an attempt was made to simulate the air interface in a testing process in a laboratory atmosphere. One example known in the art is to form a coaxial network air interface using a coaxial cable connecting a mobile station to a base station. This type of system has a number of drawbacks, in particular that isolated coaxial cables do not provide a suitable life-like radio path that is susceptible to problematic devices, such as in a real operating environment. It has a downside. A more detailed description of a coaxial network for simulating an air interface can be found in Prostom et al. U.S. Patent, entitled "Simulated Air Interface System for Simulating Wireless Communication," which was assigned to the assignee on November 7, 1995. No. 5,463,393, the details of which are incorporated herein by reference.

1 illustrates a conventional conventional coaxial network testing system used to simulate an air interface for test operation. A plurality of mobile stations collectively indicated by the reference numeral 100 are connected to the base station 110 via a coaxial cable 120, respectively. This connection consists of connecting one end of the coaxial cable 120 to the antenna port of each mobile station and the other end to the base station 110. The cable provides a shielded radio path from each mobile station to the base station, allowing multiple mobile stations to be easily tested from one location. In addition, precise control of signal strength to and from the mobile station can be achieved to provide conditions suitable for repeat testing. Computer 130 is connected to each mobile station via link 140 to automate the testing process and to monitor and record the results.

The disadvantage of using such a coaxial test network is that the same radio path is used for both transmitting and receiving signals, which unrealistically isolates the mobile station from signals from other mobile stations, eliminating the effects of co-channel interference and adjacent channel interference, for example. Will be done. This is not suitable for testing problems caused by the interaction of signals from other mobile stations, such as mass traffic testing. Mass traffic testing involves testing the system during mass registration and mass cell setup by a number of mobile stations that well simulate a life-like situation. This is an area of increasing importance because of persistent high traffic conditions that can result in access conflicts that arise from the simultaneous access of a limited number of mobile stations to a limited bandwidth channel. Thus, coaxial base networks are not suitable for this type of testing.

This problem is solved in a pending US patent application entitled "Air Interface Base Wireless Telecommunications Test System" filed November 19, 1998 by Per Green. Here, indoor antenna test systems are described that are used to test wireless telecommunication systems. The test system includes an antenna array having a plurality of individual antennae deployed in a predetermined fixed pattern within a limited testing area, such as a building or a laboratory. Further, the plurality of base stations are connected to the antenna via the antenna matrix. When the antenna matrix makes a connection between the base station and the antenna, the cell is activated accordingly. The antenna matrix can be controlled by a computer workstation to automatically activate the cells in a predetermined sequence according to a particular testing process.

If the tests are performed using a real air interface, the problem associated with conventional wireless communication test systems is that they are typically testers moving around the test area, requiring a large number of people, each manipulating the mobile phone manually. will be. Apart from hiring people, it is difficult to simulate certain types of traffic conditions, for example, accessing multiple concurrent systems. Moreover, repetition of testing is difficult when running the test environment manually. Manual operation as described above is also a factor in limiting the duration of the test.

These problems are partially solved in the system described in WO98 / 31774 entitled "Methods and Configurations for Control of Traffic Path Generation in Mobile Radio Systems", the details of which are hereby incorporated by reference. Here, the mobile station is controlled and monitored by a control computer, which communicates with a fixed part of the wireless communication system via a wireless channel. However, the test system structure described in WO 98/31174 has many improvements.

For example, in the two embodiments described in this document, computers are individually connected to each mobile station via a CAN bus. The CAN bus uses an integrated test bus protocol (UTBP) to transfer information between the computer and the mobile station, which is described as "tailor-made" for this particular application. In one embodiment, a controller module (CM) is provided to each mobile station, which, for example, interfaces the monitoring computer with the mobile station in order to translate the UTBP signal into a manufacturer specific command that each mobile station will recognize.

The structural characteristics of the system described in WO 98/31174 make it a complicated and expensive system for the manufacturer, for example, by using a dedicated controller module for each mobile station. Moreover, the dedicated wiring between each mobile station and the monitoring computer, as well as the special purpose UTBP protocol, makes it difficult (impossible) to use the existing computer network infrastructure to run the test system. In addition, such test systems are time consuming and expensive to install / modify when multiple mobile stations are connected over long distances.

In view of this, it is desired to form a flexible and economical wireless communication test system structure while easily adapting to a change in test form.

The invention will be better understood with reference to the following description with reference to the accompanying drawings, along with other objects and advantages.

1 illustrates a conventional coaxial network testing system.

2 illustrates an embodiment of a fixture of a test system including an indoor antenna system.

3 illustrates a mobile station cluster portion of a test system in accordance with an embodiment of the present invention deployed in an exemplary indoor testing area.

According to embodiments of the present invention, the drawbacks and limitations of these and other conventional test systems are solved by providing an Internet Protocol (IP) -addressable test cluster of mobile stations. Each cluster includes a plurality of mobile stations disposed within a conventional housing having IP-addressable I / O ports. The monitoring and control computer system may be operable to execute a test sequence of instructions sent to the mobile station to generate traffic in accordance with various cellular wireless communication system conditions that the system operator wishes to test. The test instructions can be individually converted into mobile station type specific instructions within the computer. The computer then attaches an IP address to each mobile station type specific command so that the command is received as a data packet by the appropriate cluster and delivered to the appropriate mobile station in the cluster.

The computer can deliver the data packet in various ways. For example, a computer may include a short range of low power “Bluetooth” transceivers for transmitting data packets over a wireless link. Alternatively, an existing wired local area network (LAN) using an IP-compatible protocol, for example Ethernet, can be used as the transmission medium of the data packet.

Embodiments of the present invention provide several advantages when compared to the test system described above. For example, the present invention utilizes a sequence of test commands that are translated into IP address data packets, thereby allowing existing mobile networks to transfer information to a mobile cluster rather than having to countless dedicated new wires to individual mobile stations. Can be used. Furthermore, by centralizing the processing of instructions and monitoring functions as well as instructions translation functions on a computer rather than individual mobile stations, the complexity and cost of implementation can be reduced. In addition, by providing an IP addressable test cluster as described herein, there is no limit on the distance between the monitoring and controlling computer system and the test mobile station and the test system, and also for the number of test mobile stations that can be used. There is no limit.

In the following description, for purposes of explanation and not limitation, specific circuits, circuit elements, techniques, and the like will be described in order to fully understand the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, and circuits have been omitted so as not to obscure the description of the present invention.

The example testing system disclosed herein is described as having an element for simulating an actual cellular wireless communication system, such as a system having a stationary and mobile unit. For purely explanation, these exemplary embodiments have a fixing portion of the test apparatus as described in the above patent application. However, those skilled in the art will understand that the IP-addressable mobile station clusters and other concepts described herein are also used in test systems in which a fixed part of the system appears using other types of test apparatus.

2 shows a fixture of an example test system. A testing structure is shown that includes seven base stations referred to collectively at 200 and connected to 21 antenna arrays, referred to collectively at 205. Note that the number of base stations and antennas can be arbitrarily scaled up or down to arbitrarily form a particular set of test conditions. The antenna is positioned in a suitable pattern to form the cell. The base station 200 is represented by a transmitter TX and a receiver RX and is coupled to the duplexer 215. The duplexer 215 separates the transmitted signal into the antenna array 205 and the received signal from the antenna array 205.

The antenna array 205 is deployed in a pattern suitable for use within the test area of the confined laboratory space. Note that the distance between the antennas can be modified to suit particular design constraints. Moreover, the distribution of antennas is managed according to the cell plan selected to create the desired testing condition. Base station 200 and antenna 205 are coupled with a lead of antenna matrix 220 to complete the connection of the individual base stations to the antenna. Leads that couple the base station and antenna to the antenna matrix 220 are typically shielded coaxial cables to provide proper signal transmission and isolation. Matrix 220 may be an off-the-shelf RF cross-connect matrix that functions by cross-connecting at least one antenna with an associated base station at any time by a linked computer workstation (not shown). have.

When connected to a base station, each antenna forms an active cell that is used to test the air interface to a suitable mobile station. The active cell can be controlled by a computer workstation, for example, to synchronize the timing of the active cell to simulate the movement of a fixed mobile station. This form of mobility is easily accomplished by manipulating the active cell by programming the workstation via an antenna matrix 220 such that a suitable base station and associated antennae are connected in a predetermined pattern. Readers interested in more information on how to simulate mobility using this example test set-up may refer to FIG. 3 and the corresponding text of the above referenced patent application.

According to an exemplary embodiment of the present invention, a test mobile of the simulated cellular wireless communication system may be implemented using an IP-addressable cluster of mobile stations connected to the monitoring computer as shown in FIG. Here, a plurality of mobile stations, for example ten mobile stations (collectively referred to by reference numeral 300 in the drawing), are disposed in the housing 310. Mobile station 300 may be an actual commercial unit or may be a "breadboard" implementation that may be reduced to the necessary electrical and mechanical components. The mobile station 300 may be detachably connected to the housing 310, for example by using a known car cradle device within the housing 310. Each mobile station may or may not need to provide its own dedicated antennae to each mobile station as shown in FIG. 3, but requires access to the antenna. To further utilize the off-the-self element, the antenna uses a known "car kit" which can connect the mobile station in the car to an antenna located outside the car to reduce the signal attenuation caused by the car's internal structure. Is implemented. If desired, the antenna can be replaced with a coaxial cable to allow another test device to be directly connected to the mobile station 300.

Each mobile station may be powered by providing a connection to a power source 320, also a 12V power source, which is also disposed within the housing 310. If a cradle (not shown) is provided in the housing to allow for removable connection of the mobile station 300 here, a power source 320 may be connected to each cradle. If desired, the 12V power supply can be implemented as an AC / DC power converter that can be connected to an external AC power source.

Each mobile station cluster includes an IP server port 330 that interfaces the mobile station 300 with the IP network 340. Port 330 has its own unique IP address and handles only data packets intended for mobile station 300 within this particular cluster. In addition to the individual ports of each mobile station 300, the IP server port 330 has external I / O connections for receiving / transmitting data packets from and to the IP network 340 and thus, IP. Server port 330 may route individual packets received by the cluster to a designated mobile station. The IP server port 330 can be implemented using an IP compatible port, but an example of a suitable IP server port is an Etherlite port.

As described above, each mobile station cluster housing 310 (and thereby each mobile station 300) is connected to an IP network 340. The network 340 can be implemented in a number of ways, for example using an existing wired LAN or using a wireless data communication system. As an example of an electronic compatible IP compatible network, IP network 340 may be implemented as an Ethernet local area network. Alternatively, a wireless IP network 340 may be provided, eg, designed according to a wireless local area network (WLAN) or recently developed "Bluetooth" technology. Bluetooth is a universal air interface in the 2.45 GHz frequency band that allows portable electronic devices to wirelessly connect and communicate over a short range of specialized networks. Readers interested in many details about Bluetooth technology are authored by Jaap Haartsen, the "BLUETOOTH-Universal Wireless Interface for Specialty Wireless Connectivity" found in the 1998 Ericsson Review, Telecommunications Technology Journal No.3. Reference is made to the titled paper, the description of which is referred to here.

IP network 340 is also connected to monitoring / controlling computer 350. Computer 350 may be any type of computer, for example a UNIX workstation. Like the housing 310, the computer 350 is also equipped with an IP compatible port (not shown), for example an Ethernet card, for communication with the IP network 340. The computer 350 provides the test operator with the ability to run various types of tests that allow the test operator to form traffic in an actual cellular wireless communication environment. The computer 350 may store a program that controls the mobile station. One or more different types of memory devices may be included, such as hard drives, nonvolatile memory, CD drives, floppy drives, and the like. The program can be implemented in one or more script files or in any other desired manner. As a purely illustrative example, without limiting the present invention, Applicants use a high-level artificial script language, for example an apparatus known as Mobile Station Subscriber Traffic Generator (MSTG) manufactured by ERISOFT, which is easy for the operator to operate. It has been noted that a script can be formed that allows the operator to easily adjust and form the script file. Alternatively, other types of scripting languages, programming languages, and the like can be developed and / or implemented for this purpose. Each script file may include a series of instructions for controlling the selected mobile station to operate in a predetermined manner at a predetermined moment to reconstruct a particular RF loading environment. For example, to test the access capability at about the same time, a script file may be stored with a series of commands that instruct all mobile stations in each cluster of the system to attempt access to the fixture. The script file may include input operations that are normally executed by the user at the mobile terminal. Those skilled in the art will appreciate that the number or type of scripts that can be stored are so varied that they cannot be described herein.

A test system comprising an IP addressable mobile station cluster according to the present invention is repeatable, such as comprising a plurality of mobile stations to test interference on a common channel of a cellular system using a carrier frequency reuse plan in a plurality of cells. Make testing easy to implement. In these test scenarios, multiple cells of mobile stations can be operated on a common channel to investigate interference related issues using a suitable set of programs or scripts. As an example, the frequency reuse distance may be selected by forming various cell patterns corresponding to cell plans such as 3/9 and 4/12. Other types of testing using the present invention include, for example, interference driven channel selection, inter-MSC handoff, traffic overload control, retry due to voice channel overrun, and base station power control issues.

The present invention is directed to a test platform that is efficient in space providing a more realistic environment for testing air interfaces. Since the actual mobile station is preferably used in the test process, handoff and interference problems due to the field can be easily investigated in the laboratory. Moreover, the true feature of testing with fixed devices provides environmental conditions that are particularly suitable for repetitive testing. Repetition of the same test allows for fine tuning of the system by optimizing the parameters and evaluating new features and algorithms under the same conditions.

The script file can be created, edited, stored and recalled using a graphical user interface (GUI) realized using the display of the computer 350. However, since the mobile station 300 is not designed to read and implement commands written in a high level scripting language, embodiments of the present invention allow converting a called script file into an earlier machine language command. . As will be appreciated by those skilled in the art, the specific type of command to which the script file is translated varies from mobile station to mobile station, based on the manufacturer, model, and the like. This conversion may be provided by a software program inherent in the computer 350, for example a so-called driver, which may be provided to each of the different types of mobile stations which are detachably connected to the cluster. If several types of mobile stations are being used for testing at the same time, for example, if several clusters 310 have different types of mobile stations within the same cluster, the computer can operate simultaneously to selectively execute the translation into the appropriate lower-level initial language. It can have a plurality of drivers.

After conversion of the mobile station type to the initial one, the computer 350 needs to send this converted command to the appropriate cluster housing 310. According to an embodiment of the present invention, this can be achieved by appending to the translated command an IP address uniquely assigned to the appropriate cluster housing. Thus, the computer 350 forms a data packet that includes the IP address of the cluster housing 310, the translated command, and optionally an individual mobile station identifier. In this way, each IP server 330 acquires each data packet associated with its unique IP address, divides this packet to obtain a mobile station identifier, and provides a command directly to the appropriate mobile station. According to embodiments of the present invention, data packetization can be performed using known asynchronous delivery mode (ATM) protocols, although those skilled in the art will appreciate that protocols having several types of data packets may alternatively be used. .

Although the invention has been described with reference to specific embodiments, this description is intended to illustrate the concept and not to limit the invention. In particular, the concept is also applicable to systems operating according to, for example, code division multiple access (CDMA). Various modifications and steps can be made by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.

Claims (18)

A system for testing a cellular wireless communication device comprising a stationary and mobile unit comprising: At least one transceiver acting as said fixture of a cellular wireless communication system for transmitting and receiving signals over an air interface; At least one cluster of mobile stations disposed in a housing, said mobile station being able to control to transmit and receive signals to and from said at least one transceiver via said air interface; And A computer for controlling and monitoring the operation of said at least one cluster of mobile stations Including, The computer is connected to the at least one cluster of mobile stations using an Internet Protocol (IP) compatible medium, And said at least one cluster of mobile stations is assigned an IP address such that said computer can address the selected cluster to a command. 2. The system of claim 1, wherein each mobile station in the at least one cluster is individually controllable cellular wireless communication device by the computer. The system of claim 1, wherein the IP compatible medium comprises a local area network. The system of claim 1, wherein the IP compatible medium comprises a wireless link. The system of claim 1, wherein the IP compatible medium comprises a public switched telephone network (PSTN). 10. The cellular radio of claim 1, wherein the computer comprises a memory element having a program stored thereon that can be repeatedly used to send several predetermined commands to the at least one cluster of mobile stations at a predetermined time using the IP address. System for testing communication devices. 7. The computer-readable medium of claim 6, wherein the computer sends each of the instructions on the IP compatible medium as at least one data packet, wherein the at least one data packet is: (a) the IP address of the at least one cluster of mobile stations; (b) an identifier of at least one of the mobile stations in the cluster that are recipients of the intended command; And (c) the command And a system for testing a cellular wireless communications device. 7. The system of claim 6, wherein the computer further comprises a driver for converting each command of the program into a command of a mobile station specific type prior to its transmission. 7. The system of claim 6, wherein the program comprises at least one script file. 8. The system of claim 7, wherein the at least one data packet is sent using an asynchronous delivery mode (ATM) protocol. In the wireless communication test unit: housing; A plurality of mobile stations disposed within the housing; And an IP compatible interface having respective connections to an I / O port with each of the plurality of mobile stations to enable data communication between the test unit and an external IP compatible network. 12. The wireless communications test unit of claim 11 wherein the I / O port is a wireless transceiver and the external IP compatible network is a wireless communications system. 12. The wireless communications test unit of claim 11 wherein the I / O port is an Ethernet device and the external IP compatible network is a local area network. 12. The wireless communications test unit of claim 11, further comprising a plurality of cradles each associated with one of the plurality of mobile stations, the mobile station being detachably connected to the housing. In a method of testing a wireless communication system: Reading a first command from the memory device of the computer to control the operation of the mobile station; At the computer, converting the first command to a second command based on the type of the mobile station; At the computer, attaching an IP address associated with the mobile station to the second command; And Transmitting from the computer, the IP address and the second command as a data packet to the mobile station. The method of claim 15, wherein said transmitting step: Transmitting the data packet using an asynchronous delivery mode (ATM) protocol. The method of claim 15, wherein said transmitting step: And transmitting said data packet using a wireless communications network. The method of claim 15, wherein said transmitting step: Transmitting the data packet using a local area network.