OPTICAL DATA INTERFACE FOR WIRELESS PHONES

Abstract: A system for connecting a wireless phone (20) to an external circuit (22). The system includes a first optical data interface adapter (42) connected to the wireless phone. The system also includes a second optical data interface adapter (24). A fiber optic cable (28) connects the first optical data interface adapter (42) to the second optical data interface adapter (24). In a specific embodiment, the wireless phone is a cellular telephone (20) and a computer (22) is connected to the second optical data interface adapter (24). The first and second optical data interface adapters (41, 24) include optical transmitters (56, 54) and photodetectors (58, 52). In an illustrative embodiment, the present invention is implemented as a system for placing wireless calls from a computer (22). The system includes a computer (22) external to the phone (20) and an optical data link (28) between the wireless phone and the computer. Software running on the computer controls the wireless phone via the optical data link (28) so that the computer can place calls via the wireless phone. In a second illustrative embodiment, the present invention is implemented as a system for taking performance measurements of a wireless phone and includes a computer optically connected to the wireless phone for transferring information between the wireless phone and the computer. Measurement software running on the computer controls the flow of the information so that the computer obtains performance information pertaining to the wireless phone.

Description: OPTICAL DATA INTERFACE FOR WIRELESS PHONES BACKGROUND OF THE INVENTION Field of Invention: This invention relates to wireless communications systems. Specifically, the present invention relates to systems and methods for transferring data between a wireless phone and another electronic device. Description of the Related Art: Many portable phones may now be controlled and interrogated using computers. In many cases, the computer can set the state of the phone or retrieve current status, condition, or levels. Hence, many measurements may be taken by linking a computer running specialized phone testing software to the cellular telephone under test. Conventional metallic conductor cables such as standard serial computer cables are typically used to connect the cellular telephone to the computer. However, when the cables are connected between the phone and computer, the cables often degrade the radiated performance of the cellular telephone. Typically, when a data cable is connected to a cellular phone, the data cable is connected to an internal phone ground, which perturbs the phone's antenna radiation pattern, significantly degrading its performance. Further performance degradation may result from radio frequency (RF) interference emitted from the cable. In short, existing wire data cables often degrade the radiated performance of cellular and personal communication system (PCS) phones. As a result, expensive acoustic devices are often required to take phone FM measurements. Infrared data linking is an alternative method for providing a data interface to a wireless phone. Typically, infrared energy is transmitted, without cables, between an infrared sensor on the phone and an infrared sensor on a computer attachment. However, the performance of the data link is degraded by bright sunlight. This is problematic in outdoor phone testing environments. In addition, the infrared data link is susceptible to blocking due objects placed between the phone and associated external computer. In addition, external electromagnetic signals from other infrared devices such as television remote controls may cause significant interference that degrades the performance of the infrared data link. Hence, a need exists in the art for an efficient system and method for transferring data between a wireless phone and an external circuit such as a computer with minimal telephone performance degradation. There is a further need for a cost-effective system that facilitates accurate cellular/PCS phone measurements in environments characterized by electromagnetic noise. SUMMARY OF THE INVENTION The need in the art is addressed by the system for connecting a wireless phone to an external circuit of the present invention. In the illustrative embodiment, the inventive system is adapted for use with a cellular telephone and an external computer. The inventive system includes a first optical data interface adapter designed for use with and connected to the wireless phone and a second optical data interface adapter. A fiber optic cable connects the first optical data interface adapter to the second optical data interface adapter. In a specific embodiment, the wireless phone is a cellular telephone and a computer is connected to the second optical data interface adapter. The first and second optical data interface adapters include optical transmitters and photodetectors. In an illustrative embodiment, the invention is implemented as a system for placing wireless calls from a computer via the wireless phone. The system includes the external computer and an optical data link between the phone and the computer. Software running on the computer controls the wireless phone via the optical data link enabling the computer to place calls via the wireless phone. Alternatively, the present invention is a system for taking measurements of a wireless phone and includes the computer, optically connected to the wireless phone. Measurement software running on the computer controls the flow of the information so that information pertaining to the wireless phone is obtained by the computer. The novel design of the present invention is facilitated by the use of the fiber optic cable for optically transmitting data to and from a computer. The optical nature of the transmission reduces or eliminates interference between data transferring across the fiber optic cable and electromagnetic energy transmitted or received by the wireless phone. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram of a cellular telephone connected to a typical data interface adapter and associated cable for connection to an external computer. FIG. 2 is a diagram of an arrangement constructed in accordance with the teachings of the present invention. FIG. 3 is a diagram of the arrangement of FIG. 2 fitted with wireless data interface adapters in accordance with the present teachings for creating a wireless data interface between the cellular telephone and the computer. FIG. 4 is a more detailed block diagram of the arrangement of FIG. 2 showing various electrical components. FIG. 5 is a flow diagram of software of the present invention for facilitating communications between a wireless phone and a computer via the data interfaces of FIGS. 2, 3, and 4. DESCRIPTION OF THE INVENTION While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility. The following review of the operation of a conventional cellular telephone data interface adapter and associated cable is intended to facilitate an understanding of the present invention. FIG. 1 is a diagram of a cellular telephone 10 connected to a typical data interface adapter 12 and associated cable 14 for connection to an external computer (not shown). Antenna currents travel along the cable 14 and tend to interfere with data transmission along the cable 14 and alter the radiation pattern of the phone's antenna system. In addition, noise generated by a digital bit stream within the cable 14 may interfere with the wireless transmission and reception of cellular communications signals via the cellular telephone 10. FIG. 2 is a diagram of an arrangement constructed in accordance with the teachings of the present invention. The cellular telephone 20 and a computer 22 are fitted with a telephone fiber optic data interface adapter 24 and a computer fiber optic data interface adapter 26, respectively. The two adapters are interconnected with a fiber optic cable 28. Antenna currents are deflected at the telephone fiber optic data interface adapter 24 and do not interfere with data transmission across the fiber optic cable 28. Noise generated by digital signals within the computer 22 is deflected at the computer fiber optic data interface adapter 26, which inhibits or prevents the noise from interfering with cellular telephone wireless signal transmission and reception. The fiber optic data interface adapters 24 and 26 may include photodetectors and transmitters (not shown) as is known in the art. These devices are commercially available. For example, the transmitters may be purchased from Siemens as SFH750V transmitters and the photodetectors may be purchased as Siemens SFH551/1-V-1 photodetectors. The photo transmitters facilitate the conversion of electrical signals into optical signals for transmission across the fiber optic cable 28. In the preferred embodiment, the fiber optic cable is a Mitsubishi EHV4002 fiber optic cable. Unlike previous approaches for providing data interfaces to cellular telephones, the unique design of the present invention facilitates the transmission of data between the cellular telephone 20 and the computer 22 without perturbing the antenna radiation pattern of the cellular telephone and without causing interference between computer electronics and cellular telephone transmissions and receptions. As a result, the present invention is ideal for applications involving the use of the cellular telephone 20 as a modem for the computer 22. In the present illustrative embodiment, software running on the computer 22 controls the cellular telephone 20 so that the cellular telephone acts as a computer modem. Additional software, as discussed more fully below, is provided for execution by the computer 22 for taking data from the phone 20 to quantify the performance of the phone 20. With access to the present teachings, the software, including the additional software, as discussed more fully below, is easily developed and implemented by those ordinarily skilled in the art. FIG. 3 is a diagram of the cellular telephone 20 and computer 22 of FIG. 1 fitted with a cellular telephone wireless data interface adapter 40 and a computer wireless data interface adapter 42 of the present invention for creating a wireless data interface 44 between the cellular telephone 20 and the computer 22. Antenna currents are deflected at the cellular telephone wireless data interface adapter 40 and noise generated by digital signals within the computer 22 is deflected at the computer wireless data interface adapter 42. The wireless interface 44 replaces the fiber optic cable 28 of FIG. 2. In the present illustrative embodiment, the wireless interface is implemented by way of optical transmission such as via Siemens laser transmitters or by way of infrared transmission via Hewlett Packard IRDA infrared transceivers. FIG. 4 is a more detailed block diagram of the arrangement of FIG. 2 showing various electrical components within the telephone fiber optic data interface adapter 24 and the computer wireless data interface adapter 42. The arrangement includes, from left to right, the computer 22, the telephone fiber optic data interface adapter 24, the fiber optic cable, the computer wireless data interface adapter 42, and the cellular telephone 20. The computer fiber optic data interface adapter 24 includes, from left to right, an RS-232 to transistor-transistor logic (TTL) driver 50 in parallel with a first photodetector 52 and a first optical transmitter 54. The fiber optic cable 28 connects the first photodetector 52 to a second transmitter 56 and connects the first transmitter 54 to a second photodetector 58, both in the optical data interface adapter 42. The second transmitter 56 and the photodetector 58 are connected to the cellular telephone 20 via standard connection systems. In the present specific embodiment, the fiber optic cable 28 is duplex plastic fiber optical cable. The interface between the TTL driver 50 and the interface between the TTL driver 50 and the first photodetector 52 and the first optical transmitter 54 are standard interfaces known in the art. The TTL driver 50 is made by Analog Devices Inc., part number ADM202EARW, Dual RS-232 Driver /Receiver. The photodetectors 52 and 58 are Siemens SFH551/1-V-1 plastic fiber optic integrated photodetectors. The transmitters 54 and 56 are Siemens SFH750V plastic fiber optic transmitter diodes. The duplex fiber optic cable 28 is Mitsubishi EHV4002 1000 micron 2 plastic fiber optic cable. In operation, TTL data to be directed from the computer 22 to the cellular telephone 20 is transferred to the TTL driver 50, which is a standard serial bus driver. As is known in the art, the TTL driver 50 can accommodate two transmit paths and two receive paths. The TTL data is formatted for RS-232 serial transmission and is transferred to the first transmitter 54. The first transmitter 54 converts the electrical serial data to serial optical data that is transmitted via the fiber optic cable 28 to the second photodetector 58 where it is converted back to electrical signals and subsequently transferred to the cellular telephone 20. The cellular telephone 20 then processes the electrical serial data via circuits such as a baseband processor (not shown) on a baseband chip (not shown). Similarly, TTL serial data to be transferred from the cellular telephone 20 to the computer 22 is directed to the second optical transmitter 56, where it is converted to optical TTL serial data and transmitted via the fiber optic cable 28 to the first photodetector 52 where it is detected and converted to electrical TTL serial data. The electrical TTL serial data is transferred to the TTL driver 50 where it is converted to RS-232 format. The TTL data is then transferred to the computer 22 for further processing. The TTL driver 50 may be replaced with another type of driver without departing from the scope of the present invention. Also, the position of the TTL driver 50 may be switched to the cellular telephone optical data interface adapter 42 without departing from the scope of the present invention. In addition, other additional drivers may be included in the interface adapters 24 and 42 and /or within the computer 22 or cellular telephone 20 without departing from the scope of the present invention. FIG. 5 is a flow diagram of software 70 of the present invention for facilitating communications between a wireless phone and a computer (see FIGS. 2 and 3) via the data interfaces of the present invention (see FIGS. 2, 3, and 4). With reference to FIG. 2, the software 70 includes routines that reside in the computer 22 and on a wireless phone computer (not shown) within the wireless phone 20. In an initial power-checking step 72, software running on the computer 22 checks if the wireless phone 20 is turned on. If the wireless phone 20 is not turned on, the software 70 ends. If the wireless phone 20 is turned on, control is passed to a command-waiting step 74. In the command-waiting step 74, software running on the computer 22 waits for requests for data and /or other user commands from a user of the computer 22. The commands and/or requests may be entered via a conventional input device such as a keyboard or mouse or a combination thereof. If in the command-waiting step 74, no commands are entered for a predetermined amount of time, the wireless phone 20 is turned off, or the user issues an exit command, the software 70 ends. Otherwise, if the software running on the computer 22 receives a user request for data /or another command other than an exit command, control is passed to a communications step 76. In the communications step 76, the software running on the computer 22 initiates communications with the wireless phone 20 (via software running on a wireless phone computer) and sends an appropriate command and /or request to the wireless phone 20 based on the command and/or request received via the software running on the computer 22 in the command- waiting step 74. Once the wireless phone 20 receives the command and /or request over the optical data interface 28, control is passed to a processing step 78, where a software routine running on the wireless phone 20 processes the request and/or command and subsequently delivers an appropriate response back to the software running on the computer 22. Details of the software routines running on the wireless phone 20 for enabling the establishment of communications and for processing requests and /or commands may be developed by those ordinarily skilled in the art without undue experimentation. Once the software routine running on the wireless phone 20 processes the request and /or command, control is passed back the command-waiting step 74, thereby forming a loop comprising the steps 74, 76, and 78 that is exited when the phone is turned off, the user issues an exit command, or the software routine times out. Thus, the present invention has been described herein with reference to a particular embodiment for a particular application. Those having ordinary skill in the art and access to the present teachings will recognize additional modifications, applications and embodiments within the scope thereof. It is therefore intended by the appended claims to cover any and all such applications, modifications and embodiments within the scope of the present invention. What is claimed is:

Claims: CLAIMS 1. A system for connecting a wireless phone to an external circuit comprising: a first optical data interface adapter adapted for use with and connected to said wireless phone; a second optical data interface adapter connected to said circuit; and a fiber optic cable connecting said first optical data interface adapter to said second optical data interface adapter. 2. The system of Claim 1 wherein said wireless phone is a cellular telephone. 3. The system of Claim 1 wherein said electrical circuit is a computer. 4. The system of Claim 1 wherein said first and second optical data interface adapters include optical transmitters and photodetectors. 5. A system for transferring information between a computer and a wireless phone comprising: an optical data interface link between said computer and said wireless phone and software running on said computer for controlling the flow of information between said computer and said wireless phone. 6. A system for placing wireless calls from a computer comprising: a wireless phone; a computer external to said wireless phone; an optical data link between said wireless phone and said computer; and software running on said computer for controlling said wireless phone via said optical data link so that said computer can place calls via said wireless phone. 7. The system of Claim 6 wherein said wireless phone includes a phone data interface adapter to said wireless phone and wherein said computer includes a computer data interface adapter to said computer. 8. The system of Claim 6 wherein said optical data link includes a fiber optic cable connecting said wireless phone data interface adapter to said computer data interface adapter. 9. The system of Claim 7 wherein said phone data interface adapter and said computer data interface adapter each include a transmitter and a photodetector. 10. A system for taking performance measurements for a wireless phone comprising: a computer optically connected to said wireless phone for transferring information between said wireless phone and said computer and measurement software running on said computer for controlling said information so that frequency modulation information pertaining to said wireless phone is obtained by said computer. 11. A method for facilitating communications between a computer and a wireless phone comprising the steps of: waiting for a user request and /or command entered to said computer by a user; initiating communications between said computer and said wireless phone over an optical interface between said computer and said wireless phone in response to the receipt of a user request and /or command by said computer; and processing said request and /or command via software running on said wireless phone in response to the receipt of said user request and/or command received from said computer over said optical interface.

Inventors: BARTLETT JEFFREY L, PORCIUNCULA LESLIE I, WALLACE RAYMOND C, BARTLETT, JEFFREY, L., PORCIUNCULA, LESLIE, I., WALLACE, RAYMOND, C.
Applicants: QUALCOMM INC, QUALCOMM INCORPORATED
Application year: 2000
Main classification: H04Q7
IPC codes: H04B7, H04B10, H04M1, H04M11, H04W88