Patent Publication Number: US-2010113011-A1

Title: Wireless electronic device testing system

Description:
BACKGROUND 
     This invention relates to electronic devices, and more particularly, to testing wireless electronic devices. 
     Electronic devices such as cellular telephones have wireless capabilities. These wireless capabilities may be used to support voice and data traffic. During manufacturing, wireless electronic devices are generally tested to determine whether their wireless functions are operating properly. For example, a test probe may be attached to a wireless device to determine whether its radio-frequency transceiver circuitry is able to properly generate radio-frequency output signals. 
     Tests may also be performed that involve transmitting and receiving actual radio-frequency telephone call signals. In a typical scenario, test equipment referred to as a “call box” is used to send and receive protocol-compliant radio-frequency test data to a wireless device under test. Call box test equipment can handle bidirectional signaling-type test transmissions similar to full-fledged cellular telephone calls. If the call box determines that the device is not performing properly, the device may be repaired or discarded. 
     The results from call box wireless tests are stored in the tested device. For example, test results may be stored that indicate the amount of power that was wirelessly transmitted to the call box from the tested device during testing. These test results may also identify the call box that was used in performing the test. The stored test results may be helpful in the event that the device ever needs to be serviced. Stored test results may, for example, be useful in improving testing and manufacturing procedures. 
     Conventional test arrangements such as these require that tested devices be tethered to the test equipment during testing. Prior to a given test, a data cable is typically connected to a device to perform setup operations. Information such as the device&#39;s serial number may be gathered. After testing is complete, test results may be stored in the device using the data cable. 
     If the test cable is removed in the middle of a test, there is a possibility that errors can arise. For example, if care is not taken, the cable might be connected to the wrong device so that test results that correspond to one device may be written into the memory of another device. Disconnecting and reconnecting the test cable is also cumbersome and can slow test throughput. 
     To avoid the potential for errors that arises from detaching the data cable during testing, testing is generally completed without ever removing the data cable from the device under test. Although this helps to prevent errors from improperly connected cables, the presence of the data cable during testing can adversely affect test accuracy. 
     Each data cable has a metal connector that plugs into the device under test. The connector is conductive and can therefore influence test results. For example, the connector may affect the radio-frequency ground of antennas in the device and may therefore have an impact on antenna performance. The connector may also provide a ground path for interference signals in the device. Interference signals may be generated by integrated circuits within the device during normal operation. When the connector is present, the grounding effect of the connector may abnormally diminish the influence of the interference circuits making device performance appear better than it should. 
     It would therefore be desirable to provide improved ways in which to test wireless electronic devices such as cellular telephones. 
     SUMMARY 
     Wireless electronic devices such as cellular telephones may communicate with test equipment using messages that are compliant with cellular telephone communications protocols such as the short message service (SMS) protocol. The test equipment may perform protocol-compliant radio-frequency signaling tests on a wireless electronic device while the wireless electronic device is in a test chamber. 
     The test equipment may include a call box and a test host. The test host may maintain a manufacturing database in which test results may be stored. The test chamber that contains the wireless electronic device under test may include an antenna. The call box may be connected to the antenna using a cable. During testing, the call box may use the antenna in the test chamber to perform wireless measurements on the wireless electronic device. The wireless measurements may include bit error rate tests, tests of receiver sensitivity and transmit power, frame error rate tests, adjacent channel power measurements, and other radio-frequency signal tests. 
     The call box may also use the antenna to send messages to the electronic device and to receive messages from the electronic device. The wireless electronic device may send a message to the test equipment that provides the test equipment with identifying information and information on the type of test that is to be performed. The test equipment may send one or more messages to the electronic device to control the electronic device during testing. For example, the test equipment may send a wireless control message to the wireless electronic device that places the wireless electronic device into a sleep mode in preparation for certain tests. Test results that are gathered by the test equipment may be transmitted to the electronic device in a wireless message. The electronic device may store the received test results in memory. 
     Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram of a wireless electronic device such as a cellular telephone that may be tested in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of an illustrative radio-frequency test chamber that may be used to test a wireless electronic device in accordance with an embodiment of the present invention. 
         FIG. 3  is a diagram of test equipment that may be used in performing radio-frequency tests using a radio-frequency test chamber of the type shown in  FIG. 2  on a wireless electronic device of the type shown in  FIG. 1  in accordance with an embodiment of the present invention. 
         FIG. 4  is a diagram of a test system of the type that may be used in testing wireless electronic devices in accordance with an embodiment of the present invention. 
         FIG. 5  is a flow chart of a conventional process for testing cellular telephones. 
         FIG. 6  is a flow chart of illustrative steps involved in testing a wireless electronic device in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention relates to electronic devices such as cellular telephones and other devices that use wireless communications. In devices such as these, it is generally desirable to perform tests during manufacturing. These tests may include tests of the radio-frequency circuitry on the device. For example, a probe may be attached to a radio-frequency (RF) connector on an electronic device. A power meter or other test equipment may monitor the power level at the RF connector to ensure that an adequate level of transmitted RF power is being produced. 
     In addition to performing probe-based tests, it is often desirable to perform wireless signaling tests. Tests such as these use protocol-compliant test equipment to communicate wirelessly with a device under test. For example, when testing a 3G cellular telephone, test equipment can be used that is compliant with 3 G communications protocols. Because this type of protocol-compliant test equipment is used in sending and receiving wireless data in a format that closely resembles that used in actual cellular telephone calls, the protocol-compliant test equipment such as this is sometimes referred to as “call box” equipment or a “call box.” Call boxes for testing cellular telephones such as the CMU200 universal radio-communications tester are available commercially from Rohde &amp; Schwarz. 
     Wireless tests performed using call box equipment may reveal whether the antennas and associated wireless circuitry in a wireless device are performing properly. If a wireless device fails a call box test, the device may be repaired or discarded. 
     A diagram of a wireless device such as a cellular telephone that may be tested using call box equipment is shown in  FIG. 1 . As shown in  FIG. 1 , device  10  may include memory  12 , processing circuitry  14 , and input-output circuitry  16 . 
     Memory  12  may include volatile and non-volatile storage such as random-access memory and read-only memory (e.g., flash). Memory  12  may also include hard drive storage and other types of storage hardware. Memory  12  may be implemented using separate integrated circuits and/or using memory blocks that are provided as part of processors or other integrated circuits. 
     Processing circuitry  14  may be used to control the operation of device  10 . Processing circuitry  14  may be based on one or more circuits such as a microprocessor, a microcontroller, a digital signal processor, an application-specific integrated circuit, and other suitable integrated circuits. With one suitable arrangement, processing circuitry  14  and storage  12  are used to run software on device  10  such as telephone call applications, email applications, media playback applications, games, business productivity applications, operating system functions, etc. Processing circuitry  14  and storage  12  may be used to help device  10  in implementing wireless communications protocols such as wireless local area network protocols (e.g., IEEE 802.11 protocols—sometimes referred to as Wi-Fi®), protocols for other short-range wireless communications links such as the Bluetooth® protocol, protocols for handling 3 G communications services (e.g., using wide band code division multiple access techniques), 2G cellular telephone communications protocols, WiMAX® communications protocols, communications protocols for other bands, etc. 
     Input-output devices  16  may be used to allow data to be supplied to device  10  and to allow data to be provided from device  10  to external devices. Input-output devices  16  may include user input-output devices such as buttons, display screens, touch screens, joysticks, click wheels, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, cameras, etc. A user can control the operation of device  10  by supplying commands through the user input devices. 
     As shown in  FIG. 1 , input-output devices  16  may include wireless communications circuitry Wireless communications circuitry  18  may include communications circuitry such as radio-frequency (RF) transceiver circuitry  20  formed from one or more integrated circuits such as a baseband processor integrated circuit and other radio-frequency transmitter and receiver circuits. Circuitry  18  may include power amplifier circuitry, passive RF components, antennas, and other circuitry for handling RF wireless signals. 
     Circuitry such as radio-frequency transceiver circuitry  20  may be connected to one or more antennas  24  by transmission line communications paths. As illustrated in the example of  FIG. 1 , one or more radio-frequency connectors such as connector  22  may be interposed within these transmission line paths. During testing, a radio-frequency probe may be attached to a connector such as connector  22 . Radio-frequency power measurements may be made using the probe to determine whether radio-frequency power is being properly transmitted from radio-frequency transceiver circuitry  20 . 
     Electronic device  10  may include a battery such as battery  26 . Battery  26  may be used to power device  10  when device  10  is not tethered to a wired source of power. 
     Device  10  may be provided with a subscriber identity module (SIM) such as SIM  27 . During normal operation of device  10  in a cellular telephone network, SIM card  27  may be used to establish a user&#39;s authorization to use the cellular services of the network. During testing, a version of SIM  27  that is designed to support test operations (i.e., a test SIM) may be inserted into device  10  to allow device  10  to make and receive calls with a call box. Test calls such as these may be similar too, but need not be identical to the cellular telephone calls that device  10  makes when used normally in a cellular network. 
     With one suitable arrangement, which is sometimes described herein as an example, device  10  may be a cellular telephone. This is, however, merely one illustrative arrangement. Device  10  may, in general, be any suitable wireless electronic device. For example, device  10  may be a portable electronic device such as a small portable computer. Device  10  may also be a somewhat smaller portable device. Examples of smaller portable devices include wrist-watch devices, pendant devices, headphone and earpiece devices, and other wearable and miniature devices. With one particularly suitable arrangement, the portable electronic devices are handheld electronic devices. Handheld devices may be, for example, cellular telephones, media players with wireless communications capabilities, handheld computers (also sometimes called personal digital assistants), remote controllers, handheld gaming devices, hybrid devices that combine features from more than one of these devices, etc. The use of handheld devices such as cellular telephone devices is generally described herein as an example, although any suitable electronic device may be tested in accordance with embodiments of the present invention if desired. 
     In addition to performing tests on device  10  by connecting a wired probe to radio-frequency connector  22 , device  10  can be tested wirelessly. As shown in  FIG. 2 , for example, device  10  may be tested by performing wireless measurements on device  10  while device  10  is in a test chamber  28 . Test chamber  28  may have sidewalls  30  that absorb radio-frequency signals and thereby help to contain radio-frequency signals within chamber  28 . This prevents interference from outside chamber  28  from affecting tests made within chamber  28 . The isolation provided by sidewalls  30  also allows multiple chambers such as chamber  28  to be operated in parallel at the same time. Even if a test is being performed in one chamber, radio-frequency signals will generally not escape from the chamber to influence tests being performed in adjacent chambers. In a typical configuration, the sidewalls of chamber  28  are configured so that chamber  28  has a pyramidal shape. 
     During tests, radio-frequency signals may be supplied to the interior of chamber  28  from call box test equipment via cable  34 , port  32 , and test head  36  (i.e., an antenna). Radio-frequency signals from test head  36  can be received by a device under test that has been placed within chamber  30  through door  38  (i.e., device  10  in the example of  FIG. 2 ). Radio-frequency signals that are transmitted from device  10  may be received by test head  36  and may be passed to test equipment such as a call box via cable  34 . 
     Test equipment that may be used in performing wireless tests on device  10  is shown in  FIG. 3 . As shown in  FIG. 3 , test equipment  40  may have an associated cable  34  that connects test equipment  40  to the antenna in test chamber  28  ( FIG. 3 ). Cable  50  may be used when it is desired to form a wired connection between test equipment  40  and device  10 . 
     Test equipment  40  may include a call box or other protocol-compliant test equipment  42  and a test host such as test host  46 . A communications path such as path  44  may be used to support communications between call box equipment  42  and test host  46 . A manufacturing database such as database  48  may be maintained by test equipment  40 . As shown in  FIG. 3 , for example, test host  46  may maintain manufacturing database  48 . 
     Test equipment  42  may be, for example, a call box for testing cellular telephones such as the CMU200 universal radio-communications tester that is available commercially from Rohde &amp; Schwarz. Test equipment  42  preferably includes equipment that is compliant with the wireless communications protocols used by device  10 , so that signaling type (call type) radio-frequency tests may be performed. For example, if device  10  supports so-called 2G, 3G, or 4 G communications protocols, test equipment  42  preferably also supports 2G, 3G, or 4 G communications protocols. 
     To control device  10  wirelessly during testing, test equipment  42  is preferably capable of sending messages to device  10 . Such messages may be conveyed using any suitable messaging scheme. For example, messages may be conveyed that are compliant with short message service (SMS) protocols. Message protocols such as SMS message protocols are defined as part of the 3GPP 3G partnership project protocols. In particular, SMS message protocols form part of the Global System for Mobile portion of the 3GPP standard as set forth in the TS23 3GPP specifications. 
     If desired, different pieces of equipment may be used to support message communications functions and radio-frequency test call functions. For example, one test unit may be used to send and receive messages such as SMS messages and another unit may be used to handle test calls with device  10 . Although schemes such as these may be used, it is generally preferably to use a call box for equipment  42  that is able to handle both messaging operations and signaling-type tests, as this may help to minimize test equipment complexity. If desired, test equipment  42  may include power meters, spectrum analyzers, and other such test equipment. 
     Path  44  may include wired and wireless paths (e.g., local area network paths based on wireless standards, Ethernet cables, etc.). 
     Test host  46  may be implemented using a personal computer, a workstation, other such computers, a network of computers, remote servers, or any other suitable computing equipment. Test host  46  may share test data with other computer systems such as computer systems that are associated with the engineering department of a device manufacturer or computer systems that are used by service personnel. In a typical test environment, devices are tested and test results are stored in each device. Full or abbreviated test results may also be stored in databases such as manufacturing database  48 . The test results can be statistically analyzed to determine whether design changes or manufacturing changes can be made to improve yields, performance, and reliability. 
     A typical test environment that may be used when testing devices such as device  10  of  FIG. 1  using test equipment such as test equipment  40  of  FIG. 3  is shown in  FIG. 4 . As shown in  FIG. 4 , in test system  52 , test equipment  40  may communicate with device  10  using wireless path  54  or wired path  50 . Wired path  50  may be formed during an initial setup process, may be formed when it is desired to save test results in device  10 , or may be omitted entirely to streamline the test procedure. Communications over wireless path  54  may be supported by transmitting and receiving radio-frequency signals between test equipment  40  and device  10  using cable  34  and antenna  36  in test camber  28 . 
     Conventional testing techniques rely on the use of a wired path such as path  50  that connects test equipment directly to a device under test. The steps involved in conventional wireless testing of a cellular telephone while using a wired connection are shown in  FIG. 5 . 
     Conventional test approaches require that test equipment be connected to a wireless device by a wired connection such as a cable terminated with a 30-pin connector that plugs into the wireless device. This connection may be made when initiating test operations (step  56  of  FIG. 5 ). The device to be tested may be placed in a test chamber prior to performing wireless tests. 
     After personnel at the manufacturer have attached the test equipment to the cellular device with the cable, the cellular device may be set up for testing at step  58 . During step  58 , information that is specific to the device that is being tested such as the device&#39;s serial number may be conveyed to the test equipment and entered into a database. 
     After setup operations are complete, wireless tests may be performed (step  60 ). These wireless tests may involve making test telephone calls (or their testing equivalent) using call box equipment. 
     Following testing at step  60 , test results may be written from the test equipment into memory in the tested device using the wired connection between the test equipment and the wireless device. The test results might indicate, for example, that the device was tested by a particular piece of test equipment and that the test equipment measured a particular transmitted power level when the device was directed to produce a given radio-frequency output signal during testing. 
     Although the conventional test approach of  FIG. 5  may sometimes be satisfactory, it can lead to test errors. During the operations of step  60 , the cable connector that was attached to the device at step  56  remains plugged into the device. This can affect wireless test results by altering the ground properties for the antennas in the device and by creating an unnatural ground path for interference signals. The tests that are performed at step  60  may therefore not be accurate. 
     Illustrative steps involved in testing wireless devices such as cellular telephones in accordance with an embodiment of the present invention are shown in  FIG. 6 . 
     Testing of device  10  may be initiated by an operator. As indicated by line  64 , an operator at a manufacturer may place device  10  in test mode by launching a diagnostic program on device  10 . The diagnostic program may be launched, for example, by entering a service menu and selecting an appropriate on-screen option, by pressing a particular sequence of buttons on device  10 , etc. 
     After the diagnostic program has been launched, the program turns on radio-frequency circuitry in device  10  and initiates a discovery process. Once the diagnostic program has been launched, the operator may insert device  10  into test chamber  28  through door  38 . To avoid the testing inaccuracies that may arise when performing tests while device  10  is connected to the test equipment with a wired connection, device  10  may be placed in the test chamber  28  without any attached test cables. 
     While in test chamber  28 , the diagnostic program can direct device  10  to perform setup operations to ensure that device  10  is properly configured for testing. These setup operations may involve turning on a baseband processor and other radio-frequency transceiver circuitry  20 , confirming that a test SIM such as SIM card  27  of  FIG. 1  is present within device  10 , and configuring device  10  to make and receive suitable test calls (using, for example, Global System for Mobile or Universal Mobile Telecommunications Systems protocols). 
     The discovery process that is initiated by running the diagnostic program on device  10  may use wireless communications circuitry  18  to communicate with test equipment  40  and thereby locate the call box to be used for testing. 
     At step  68 , after device  10  has been placed in test chamber  28  by the operator, device  10  wirelessly registers with call box  42  in test equipment  40 . 
     If the registration process fails (e.g., due to a defect in device  10 ), test host  46  may record the failure in manufacturing database  48  (step  70 ). Test host  46  may then signal the operator to remove device  10  from test chamber  28  (step  72 ). For example, test host  46  may create an audible alert or message or may present instructions for the operator on a computer monitor in test equipment  40 . 
     If the registration process of step  68  is successful, testing may proceed to step  74 . At step  74 , device  10  may send a wireless message to call box  42  in test equipment  40 . The wireless message may be transmitted in any suitable message format. For example, the message that is transmitted may be compliant with cellular telephone communications protocols such as the short message service (SMS) protocol. This is, however, merely illustrative. Other message formats may be used if desired. 
     The message that is sent to the test equipment at step  74  may include information that helps call box  42  and equipment  40  to prepare for a wireless test of device  10 . For example, the message may include information on the serial number of the device under test or other device identity information that uniquely identifies device  10 . The message may also include information on the capabilities of device  10 . As an example, the message may include information on which communications protocols are supported by device  10  (e.g., 2G, 3G, etc.) and which communications bands are supported (e.g., 850 MHz, 900 MHz, 1800 MHz, etc.). Device  10  may also include information in the message on which firmware version is installed on device  10  and information on the device type (e.g., a version number for the device). The wireless message may also include information on which type of test should be performed. This test type information may, for example, be generated automatically by the diagnostic program or may be selected by the operator as the operator interacts with the diagnostic program. The test type information may specify which wireless features of device  10  are to be tested (e.g., which communications bands are to be tested, what types of measurements are to be made by equipment  40 , etc.). 
     If some of the information in the wireless message was previously supplied by device  10  to test equipment  40  (e.g., in an earlier wireless message or over a wired connection formed using wired connection  50  during a wired setup operation), redundant information may be omitted from the wireless message of step  74 . 
     Call box  42  may receive the wireless message that was sent from device  10 . At step  76 , call box  42  may forward the received message and its contents to test host  46 . 
     At step  78 , test host  46  may receive the forwarded message from call box  42  and may initiate testing. During testing, test equipment  40  may use call box  42  to perform wireless tests in accordance with the test type instructions contained in the message from device  10  and/or in accordance with test instructions supplied by an operator at test host  46 . Testing may be performed over any suitable range of communications bands and channels. For example, testing might involve making a series of telephone calls in a given communications band (e.g., 1800 MHz) for each of multiple channels within that band (as an example). Test measurements that may be made during a call between call box  42  and device  10  include transmit power, receiver sensitivity, bit error rate (BER), frame error rate, adjacent channel power, etc. These are merely illustrative examples of the types of measurements that may be made. Any suitable test equipment  40  may be used to make test measurements and, in general, any suitable tests may be implemented. 
     An advantage of using protocol-compliant test equipment such as call box  42  in performing the tests of step  76  is that this type of test equipment is able to perform tests that simulate actual cellular telephone calls by exercising high-level features in the cellular protocols. Device  10  is preferably loaded with a test SIM prior to testing, so device  10  is able to handle test calls just as if device  10  were establishing a wireless cellular link with regular cellular telephone network equipment. More basic measurements (e.g., power meter measurements and frequency spectrum measurements) may also be made during testing if desired. These measurements may be made using stand-alone equipment (e.g., a power meter or spectrum analyzer that is separate from a call box) or the functions available within the call box may be used to perform power and spectrum measurements). Device  10  is preferably contained within chamber  28  during testing, so that radio-frequency test signals that are created during the test (i.e., link  54  of  FIG. 4 ) do not generally generate interference for nearby devices that are being tested in parallel. During tests, host  46  may serve as a master and call box  42  may serve as a slave (as an example). 
     The results of the tests that are performed by test equipment  40  during step  78  may be stored in a database. For example, test host  46  may store test results from call box  42  in manufacturing database  48 . The test results may be shared with other databases if desired. 
     At step  80 , test host  46  may direct call box  42  to store test results from the test of step  76  in device  10 . In response, call box  42  may wirelessly transmit some or all of the results of the tests to device  10  for storage in memory  12  ( FIG. 1 ). Test results may be transmitted from call box  42  to device  10  using any suitable arrangement (e.g., in a message such as an SMS message). 
     At step  82 , device  10  may store the test results that have been received from test equipment  40  in memory  12 . Some or all of the test results may be stored. Examples of test results that may be stored include results related to measured transmit power, receiver sensitivity, bit error rate (BER), frame error rate, adjacent channel power, etc. Test data may also reflect the results of radio-frequency power measurements and measurements from spectrum analyzer equipment. 
     Test results may include information about the test equipment that performed the tests. For example, identifying information such as a station identifier (station ID) or other identifier that identifies call box  42 , test host  46 , and other components in test equipment  40  may be included in the test results that are wirelessly transmitted to device  10  and stored in memory  12 . 
     The test results that are transmitted to device  10  may also include information on the date and time at which the test was performed, information on the location at which the test was performed, other information about the test environment, etc. This data may be stored in memory  12  in a secure location (e.g., in a secret and potentially encrypted location that is accessible only to service personnel). In the event that device  10  is serviced, the test results may be examined by service personnel. A database may be maintained by the service personnel that links service issues with particular test results information. The data in this type of database may be analyzed to identify manufacturing trends such as trends in yield and reliability and testing issues. Service database content may be linked with or incorporated into manufacturing databases such as database  48  of  FIG. 3 . 
     After the test results from test equipment  40  have been stored by device  10 , device  10  may wirelessly transmit one or more optional confirmation messages to test equipment  40  (step  84 ). A confirmation message may, as an example, be sent in the form of an SMS message. The optional confirmation message may serve as a form of handshaking that informs test equipment  40  that the test results have been successfully stored. If the test results are not properly received, device  10  may send a command to test equipment  40  requesting that the test results be retransmitted. 
     After test equipment  40  receives the confirmation message, test host  46  may signal the operator that testing is complete and that device  10  may be removed from test chamber  28  (step  72 ). 
     If desired, multiple tests may be performed without removing device  10  from chamber  28 . For example, rather than sending a confirmation message at step  82 , testing may continue at step  74 , where device  10  can send a message that informs test equipment  40  of additional tests that should be performed. If a first test was performed in a first communications band, a second test might, as an example, be performed in a second communications band. Additional testing may also be used to test additional aspects of the wireless performance of device  10 , to test additional channels in a given band, etc. In situations in which multiple tests are being performed, it may not be necessary during subsequent test loops for all of the setup parameters in the SMS message of step  74  to be resent from device  10  to test equipment  40 . For example, the first time that device  10  sends a wireless message to test equipment  40  to set up a test, device  10  may provide information on the capabilities of device  10  and the device&#39;s serial number or other identity information. In the event that processing loops back to step  74  to set up additional tests, it may not be necessary to resend this information to test equipment  40 . 
     If desired, test equipment  40  and device  10  may communicate with each other during testing using wireless messages. For example, during the testing operations of step  78 , call box  42  may send wireless test control messages to device  10 . These test control messages may serve as commands for device  10 . Test equipment  40  may send a command to device  10  to place device  10  in a desired configuration before performing a particular portion of a test. As an example, if it is desired to perform wireless testing while device  10  is in sleep mode, test equipment  40  may transmit a wireless message to device  10  during testing that instructs device  10  to enter a sleep state. Once device  10  has entered sleep mode in response to this command, test equipment  40  may perform appropriate tests. 
     The ability to communicate between test equipment  40  and device  10  using wireless messages during testing (i.e., during step  74 ) may also be helpful in situations in which handover functionality is not available in equipment  40  to support continuous device testing. When equipment  40  that does not support this type of testing functionality is used, it is generally necessary to perform a new setup process each time a different test is desired. By sending wireless messages during testing, some or all of these setup operations may be avoided. A continuous set of tests may therefore be performed with necessary changes to the operating mode of device  10  being handled by real-time wireless commands from test equipment  40 . 
     With the wireless messaging schemes of the present invention, there is no need to reestablish a communications link (link  54  of  FIG. 4 ) between device  10  and call box  42  before testing can continue. By sending test commands from call box  42  to device  10  in the form of wireless messages and by receiving associated wireless messages from device  10 , test equipment  40  may perform a continuous set of tests (e.g., tests for different communications bands) without reestablishing communications link  54  in a new set up process (i.e., a setup process of the type described in connection with launching the diagnostic program, registering the device, etc.). 
     If desired, some communications between test equipment  40  and device  10  may be performed using wired connections. For example, a wired connection may be formed using a cable such as cable  50  of  FIG. 4  during setup operations. With this type of arrangement, wireless messages such as those transmitted from device  10  to test equipment  40  during step  74  may be supplemented or replaced by wired communications transmitted over cable  50 . A wired connection may also be used after testing is complete to store test results in device  10 . This arrangement may be used to replace or supplement the wireless transmission of test results to device  10 . 
     The foregoing is merely illustrative of the principles of this invention and various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention.