JPH07500473A - Mobile device-to-mobile device communication in cordless telephone systems - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Portable device-to-portable device communication technology field in cordless telephone systems TECHNICAL FIELD The present invention relates generally to communication systems, and more particularly to cordless telephones (simplified mobile telephones). ) related to the field of systems.

Background of the invention Portable cords such as second generation digital cordless telephone (CT2) systems A wireless system typically has a large number of call point stations (5 ta). tion) and each provides a number of radio (RF) channels. these A call point station is also called a telepoint or cordless fixed part (CFP). .

CFP is a mobile telephone handset (also known as cordless portable part, CPP). access to the Public Switched Telephone Network (PSNT). This is to make it possible to do so. CPP allows access to the PSTN. Comes within range of telepoint (CFP), CCP (/-ndose7to) is CF This is after establishing a synchronization link with P (base station).

In the CT2 system, a hand cent that makes a call to a base station The handset corresponds to a certain radio frequency (RF) channel in Transmits asynchronously on one available channel of the transceiver (each base Local stations can pay for up to 40 channels).

In a typical CT2 system, the communication protocol standard defines four main burst structures: They include multiplex 3 (MUX3), multiplex 2 (MUX2) and multiplex 1 (MUXI), and multiplex l is further called multiplex 1.4 or 1.2 (MU XI.

4 or MUX1, 2). MUX3 is mainly used from CPP to CFP. used for communication link initiation (link establishment and re-establishment). MUX 2 is mainly used for establishing the communication link and initiating the link from the base station (CFP). used. MUX 1 burst structure (MUXl, 2 and MUXl, 4) is Voice/data communications, signaling information n), and control messages from CPP (portable device) and CFP (base) used for.

To better understand the communication protocols of the CT2 system, please refer to the Europ ean Telecommunications 5standardsInst Published by itute on June 30, 1991, rCommon ai r　1nterface　5specification to be used for the Interworking beIween cordles s telephone equipment in the frequency y band F164.1 MHz Io 868.1 MHz, incl uding public access 5 services J (1.1 edition ), the contents of which are incorporated by reference into this application.

In today's CT2 systems, all communication is between the CPP and CFP, typically Basically, the CPP calls the CFP, but the CFP also calls each CPP. You can also make a call. Using the C70 protocol standard (CAI), The calling radio handset (CPP) uses MUX3 to send the call to the base (CFP). Transmits asynchronously on available radio frequency channels, and the base station and wait for the ball by one of the CPPs in the system.

The table in Figure 1 shows the cordless portable unit (CPP) and telepoint base station (CFP). 2 shows a typical handshake sequence during operation. Matrix 100 is link setting direction, message direction, MUX mode, and each handshake sequence This shows the contents of the link identification code (LID) for the link. The LID code is as follows. It is used for

1) Terminal point identification for CPP (hand cent) call setup; 11) Hand station During link exchange and link re-establishment, the CPP (handsect) and C Link reference for FP (base): and 1ii) a ringing address to which one or more CPPs respond; ss), the base identifier (BID).

Line 102 shows how the handset (CPP) is connected to the telepoint (CFP) Line 104 shows the basic sequence of operations for establishing communication with the telepoint Further, line 106 shows how the client station establishes communication with the handset. , how to restart a communication link if it is destroyed during a communication session. Indicates whether to establish. Taking row 102 as an example, the specific handset (CPP) and base The series of operations that occur to establish a communication link with a ground station (CFP) is shown. be done. The requesting hand point (CPP) transmits the hand point at MUX3. Send a message containing an identification number (termination point ID). Next, the base station uses MUX2 communication link to notify the handset that it has been linked. send a message containing the LID with the reference identification number.

Once a communication link is established between these two devices, the device will Proceed to protocol and the CFP will send supervisory messages. sage) and submit approval. Functions of both cpP and CFP (capab permissions) are determined and permission to use the system is determined by the CFP. Determined by These two devices are then ordered by the CFP and the CPP. Upon approval, it moves to the MUX1 protocol. In MUXl, once If the dial tone is sent by the CFP, the CPP must enter the telephone number it wishes to access. dial the number.

Finally, a voice communications link is established between the CPP and the telephone number side of the dialed number. be erected. Voice messages may be sent to the MU depending on the particular system 100 used. It is transmitted using either Xl,2 or MUXl,4.

As mentioned earlier, in today's CT2 systems, CPP only communicates with CFP. possible, but again as mentioned earlier, if either device makes a call to the other. It can be carried out.

As CT2 systems become more widely used, There is a need for a way to allow cpps to communicate directly with other cpps without Ru. Additionally, this objective can be achieved while operating under the CT2 communication protocol standard. That would be desirable. By doing this, CT handset users can Figure 1 shows how cordless telephone equipment (CPP) ) and the telepoint base station (CFP) using conventional technology. The matrix of continuation operations is shown.

FIG. 2 is a diagram illustrating a typical CT2 system according to the present invention.

FIG. 3 is a diagram illustrating a CPP-to-CPP registration process according to the present invention.

FIG. 4 is a diagram illustrating CPP-to-CPP link establishment according to the present invention.

FIG. 5 is a block diagram of a cordless telephone according to the present invention.

Detailed Description of the Preferred Embodiment Referring now to the drawings, and in particular to FIG. 2, a cordless telephone system 2 according to the present invention is shown. A communication system such as 00 is shown. Cordless telephone system 200 is a Preferably, it is a second generation cordless telephone system, and is even better known as the CT2 system. It is well known. Cordless telephone system 200 includes one or more bases. Ground station (CFP) 204, 208 and one or more handsets (CPP) 2 10,212.214.216. Each of the CFPs 204 and 206 is connected to a public telephone It is coupled to a telephone switching network (PSTN) 220 . Once the handset Gaining access to one of the RF channels provided by a given base station The base station establishes a communication link between the requested handset and the PSTN 210. , which allows the handset user to connect to a landline partner. You will be able to make standard phone calls to your party. system 20 0, the base station 204 has a typical dynamic range indicated by the communication coverage area 202. base station 208 is shown as having an active area 206; .

When a handset enters the base station coverage area 202 or 206, the handset An attempt is made to gain access to one of the base station communication channels. be able to. Handsets typically have a maximum output power of approximately 10 milliwatts (mW) It is a very low power portable communication device with a power rating of .

Each base station, or telepoint 204, 208, has up to 40 communication channels. can be borne. When you request access to a certain base station, the handset Scans the RF channels of the base station and identifies available channels (e.g., unused channels). channel). At this point, the handset has Sending a link request, the base station can send a reply using MUX2.

Next, handshake at MUX2 and handset are performed between these two devices. A check is performed on the phone ID and the phone calls the particular calling handset by [+1]. C The set ID is used for billing purposes and to ensure that only authorized equipment uses the system. It is used by both parties to ensure that the

Establishing a handset-to-handset (CPP-to-CPP) communication link according to the present invention In order to establish (Handset Identification Code) and HIC (Handset Identification Code) and MIC (Manufacturer Identification Code). Using the PID (Product Identification Number) of the called handset in the field (separate code) Then, the ball message of MUX2 of the base station is emulated. preferred In particular, this pole has a unique intonation ring cadence. It communicates that outgoing and incoming calls are coming from the hand center and not from the base station. Identify the user of the destination handset. Once the link is established, the call can be made The local handset continues to emulate the base station throughout the call. this The handset acts as a timing mask for the duration of the conversation. including Using the method of the present invention, a handset having such a structure is compatible with any C70 Common Air Interface (CAI). A direct link can be established with a handset (CPP). rcpp The two key features for achieving “CPP-to-CPP calls” are: 1) CPP-to-CPP registration; and 2) CPP-to-CPP link establishment, both of which are updated below. will be discussed in detail.

FIG. 3 shows a registration process 300 according to the present invention. This registration process A configuration process that allows a set of handsets to interact directly with each other.

Preferably, a handset-to-handset communication function (CCC) according to the present invention is featured. The featured handset has a number of registration slots and a random base identification code ( BID). Random base identification code identifies a specific handset , other registered handsets are intended to receive calls from it. Ru.

In addition, handsets capable of handset-to-handset are separated separately. Includes a registered slot to accept calls from incoming handsets at the user's discretion. enable and disable, thereby identifying unwanted handsets. be able to prevent certain handsets from establishing access. Good too. Typically, CT2 handsets are usually sold through retail stores, so In order for the handsets to communicate directly with each other, a registration process as shown in Figure 3 is required. A recording process is required. However, certain groups of handsets can communicate directly with each other. If you know in advance that you will need to register (CCC), you can provide registration information (e.g. , ID of a handset that can directly communicate with a specific handset), at a service shop. Each radio could be programmed manually or during the manufacturing process.

If both handsets are capable of handset-to-handset communication (if (either handset can make calls to the other), the registration process is Bidirectional, only one hand can be handset-to-handset. If there is (e.g. in this particular case only CCC capable handsets ), it is unidirectional.

Users of CPPI handsets will be able to communicate at a later date and one handset (this In the particular example, this is handset CPP2). Begin the registration process by selecting . Next, the user Press the SET key successively to start the registration process. At this point, the hand Set CCPI includes link identification code = rFFFFJ and scans MUX3. Start. Handset CPP2 at the same time for handset CPP1 Select CFP (base station) registration slot. The CeF2 handset is then Standard CFP over the air registration ) via the handset keypad.

The airborne registration step is performed by the mobile handset (CeF2) and first the MU Initiate a link request 302 for X3.

where Handcent Identification Code (HIC) and Manufacturer Identification Code (MIC) is equal to the CPP2 portable device identification code (PID). Link identification for sky registration The code is set equal to IFFFFJ. Channel marker bit A pattern (CHMP) is also sent in this transmission. Receiving handset The CPPI simultaneously scans available wireless channels in MUX3, Find LID equal to rFFFFJ. Once CPPI receives such a LID If so, the device opens communication at MUX2, as shown in step 304. start A linking message 306 is sent by CPPI. This meal The message is set equal to CPP2's PID and LID, link reference identification number. Contains 5YNCF (synchronization word from CFP). In step 326 , CPP2 contains the PID of CPP2 and 5YNCP (synchronization word from CPP). sends an identification reception message (rI D-OKJ) CPP2 then performs a layer 2 link protocol initialization process in step 308. command (layer two 1 ink protocol 1 initial ization command) to the CPPI. This command It is called constant asynchronous balance mode message (rSABMJ). on the other hand, Following this, in step 310, the CPPI acknowledges the SABM message. Ru. Also in steps 308 and 310, all state variables (V (r) = receiving local state variable and V(s) = sending local state variable) and data confirmation Establishment request (DL EST REQ) and data establishment (DL EST IND) Instructions are reset.

In step 308, CPP2 selects the configured asynchronous balance mode (SA BM) Send the message to CPP 1. SABM is Layer 2 Link Pro This is a protocol initialization command. Following this, the SABM acknowledgment message is sent to CPP 1 to CPP2. At this point in the registration process, CPPI and C A communication link is established with PP2.

In step 312, CPP2 includes information of any activated mechanisms. , its own function (TERM CAP.

terminal functions) to the CPPI via element rFAJ. Also, the sticker At step 312, CPP2 identifies its manufacturer identification code (VANIC) and The manufacturer CPP model identification code (IODEL) will also be notified to CCPI.

Then, in step 328, CPP 1 activates its functions (BASCAP, main In the invention, CPPI emulates a base station, so the base function) Then, notify CPP2. In step 314, the CPPI and PID, and notify CPP2 that CPP-CPP registration is possible. send a message to CPP2 then retrieves the information in step 316. acknowledge receipt of information.

Then, CPP 1 issues on-air registration approval (on-air registration) in step 318. registration acknowledgment) (OA RA) and in step 320 CPP2 acknowledges receipt of this 0ARA.

In step 318, CPP2 stores the BID of CPP1 and In step 320, CPP 1 The PID of CPP2 is stored in the assigned registration slot. Step 322 Smell , the CPPI sends an initialization information element (INIT) and returns to step 324. At this point, CPP2 acknowledges receipt of INIT. At this point, CPPI and C Now that the PP2 registration is complete, these two handsects have communicated directly with each other. You can do it whenever you want.

Referring now to FIG. 4, a CPP-to-CPP link establishment procedure according to the present invention is illustrated. It is. This procedure allows one handset to communicate directly with another handset. request that

In this particular example, CPPI desires to establish a communication link with CPP2. Rin The network establishment protocol diagram 400 shows that the CPPI was previously established in the registration process. It begins by selecting a registration slot for CPP2. Once CPPI users Press the appropriate key entry on the CPP1 keypad to establish a communication link with CPP2. If the CPP 1 handset requests the establishment of the M Send UX2 ball message. By Paul Message's CPP2 If the reception is successful, CPP2 sends a response to the ball. This pole is also M It is transmitted in UX2. Both devices then perform steps 404 and 40. At 6, handshake ID-OK code words are exchanged.

Next, a ring signal message is sent in one step. It is sent in step 408. As mentioned above, the ringing signal message is If the transmission originates from the Handsent and not from the Telepoint. in a different way □ so that CPP2 can be notified that It can include parameters that can signal a call.

In steps 410 and 412, the two handsets are Message ID-0K messages are exchanged with each other.

Following this, in step 414, CPP 1 sends a message and Notify the ringer circuit of PP2 to stop . Steps 404 through 414 include selecting a special intonation ring tone (duty cycle). ) is repeated to occur.

To answer the call at this point, the user of the CPP2 handset must activating the device's "line key" switch on the client, and in step 416 Generates a link request message. A link request is used to obtain a communication link. , which is required by CPP 2. CPP 1 receives the request; Then, in step 416, a linking message is sent. This message At the step, the CPPI sends a CFP authorization and assigns a call reference identification number.

The CPP2 sends an identification-ok message. ssage) in step 418, and then in step A layer 2 link protocol initialization command (SABM) is sent at 422. It will be done. The CPPI then approves the command at step knob 424. Once initial If the conversion command is approved, a communication link between the two handsets is established. It turns out. As previously mentioned, steps 422 and 424 include In order to keep the communication synchronized between all state variables (V(s) and V(r)) Initialize to zero.

The CPP2 device then informs the CPPI of its capabilities in step 426. Send a message. In step 428, the call termination message is sent to the CPP. 2, which completely turns off paging on CPP2. CPPI is Following this message, in step 430, the CPP2 Send a message to notify. Next, in step 432, the channel control menu Sausage (CC) is transmitted at MUX2. At step 434, CPP2 acknowledges the channel control message at MUX1. step At 436, another channel control message is sent, this time to MUX 1 It is sent by CPPI using the protocol 1. CPP2 also steps 438 1 and acknowledge this message using the MUX1 protocol. Once this Once these steps are completed, the device is connected to the B channel. B-chan A channel is a 32 kilobit (kbit) per second voice or data channel. , here used by said device to transmit those data or voice conversations. I can stay. The devices continue to communicate until one of them decides to discontinue the conversation. , this bidirectional MUX 1 transmission is held. When a decision is made to cancel, the traditional cancellation rules apply. Accordingly, the B channel is released and the devices are returned to their standby state.

In the present invention, a CCC ball is received at MUX 2 (step 402) Therefore, cpp wait behavior is not changed due to CCC41 functionality. In addition, CFP Since only MUX3 link requests are monitored, CFP or BID collisions can be avoided. This eliminates collisions of outgoing CCCs. Using the present invention A CPP (CPP1 in this particular case) that has CCC functionality is connected to MUX2 CFP monitors only the balls (excluding registration and link re-establishment). This will eliminate link request conflicts. CCC link re-establishment is CPP-CFP The calling CPP performs CFP emulation and re-establishes the link. During the standby period, a MUX3 link request is received from the called CPP and a scan is performed.

During the link establishment procedure of the present invention, the calling handset (CCPI) performs CFP (base station) emulation and transmits the second hand cent (CeF2). ) establish a communication link with CFP emulation using CPP 1 , CPPI serves as a synchronization mask for frame, burst, and bit synchronization. including. In the previous example, CeF2 records its frame, burst and bit clock. synchronize the clock to the signal received from the CPPI. Also, Shibeken CPP vs. CFP Ri In link establishment, the CPP sends the ball at MUX3. I transmits the link establishment ball (402) by emulating CFP by CPPI. This is done in MUX2 as part of the ration. This usually allows CT2 printers to Other cPPs scanning in MUX2 under the protocol are in their standard operating mode. It becomes possible to receive the ball from MUX2 without changing the code.

As discussed earlier, emulation of CFP in CPP is based on MUX2. CT2 common air interface, such as sending a link establishment ball in Some of the base station communication protocol parameters established by the standard (CAI) CPPI does some emulation, timing mask , and emulations of other CFPs such as those shown in Figures 3 and 4. nothing. Also, the MUX 3 scans the link request (step 302) CPP17) The registration process also includes CPP1i,:! CFP emulation CPP normally does not perform scanning in MUX3.

FIG. 5 shows a simplified cordless telephone 500 according to the present invention. A block diagram is shown. The cordless telephone 500 includes a known RF transceiver 502. and transmits and receives RF communication signals through an antenna 504. CT2 handset The above-mentioned rMPT1375 Common Air Interface 5 specification (CAI) J. This is a moth 1ms incoming and outgoing frames separated by a code time segment It establishes a time division multiplexing protocol with alternating In some multiplex configurations , each transmit/receive segment consists of a B channel (64 bits) and each end of the B channel. and a D channel containing 1 or 2 bits.

A time division multiplexer (TDD) 506 performs time division multiplexing and transmit/receive functions of digital signals. and a transceiver 502 that performs frame formation. ADPCM/C0DE C508 receives the audio signals generated by microphone 510 and to be processed for sending. The APCM/C0DEC508 connects the speaker 512 to It also performs processing to make the audio signal audible.

Controls programmed in a known manner, except for modifications to obtain the functionality of the present invention. A control means, such as controller 514, controls the operation of cordless telephone 500. system Controller 514 may be any one of a number of microprocessors or microcontrollers. However, the controller may have an input/output function and a built-in memory. preferable. Controller 514 allows telephone 500 to communicate directly with other cordless telephones. change the behavior of cordless telephone 500 whenever it becomes necessary to Run the program. Controller 514 determines which MUX level to use. communication protocol parameters, such as whether to send information packets, and , while keeping the phone 500 compliant with the CT2 communications protocol standard (CAI). , the telephone 500 is configured to be able to communicate directly with other telephones. Automatically change other parameters that need to be simulated.

For example, controller 514 may change the operation of telephone 500 to A link establishment message that essentially emulates a message sent by message (as shown in step 402) so that phone 500 can communicate directly with other phones. enable communication. The controller 514 also sends a link request message to M For the operation of scanning UX3, we performed base station emulation (see Figure 3). This allows phone 500 to register with other phones (as shown in step 302). This is something the CT2 phone does not do.

The subscriber interacts with the cordless telephone through keypad 516. Key Bud 516 allows the device user to use the CCC (handset) taught by the present invention. implementing operational features of the telephone 500, such as handset-to-handset communication); be able to. Display device 520 provides visual interaction for the subscriber. be. Memo such as electrically erasable programmable read-only memory Re-block 522 stores the handset ID number and other important information. Ru.

Memory block 522 may also include a RAM portion for temporary storage of information. can.

The present invention extends the functionality of the CT2 handset so that the RF link passes through the CFP. You can communicate directly with the handset on the same floor without having to use the CT2 common air. interface (CAI) protocol standard to maintain full compliance. It is something to do. To establish a CPP-to-CPP link, the calling CPP Enter D in the LID field, emulate CFPMUX2, and The target CPP enters the PID in the HIC and MIC fields. Next, Iriki so that CPP users know that calls they make are from handset. Optionally, the pole is sent out using a unique intonation ring tone. Once the link is established If set, the calling CPP continues to emulate the CFP during the call. . Using the inventive approach, a handset with this feature can be used with Cr2 CAI You can establish a direct link with any hand cent that is compatible with Ru.

In summary, the present invention utilizes CT, a two-standard common air interface standard. If a radiotelephone handset operating under It allows you to communicate directly with other handsets without having to do so. Also , the present invention allows handset users to connect not only to the PSTN but also to other handsets. Users can also form direct links, making the communication system more flexible. It is what makes the system possible.

Figure 1 (Conventional technology) Figure 2 Special Table Sen7-500473 (9) Figure 5

Claims (8)

[Claims] 1. a base station and a second radio, the base station having a set of predetermined parameters; In the communication system, the communication system communicates with the second radio using a communication protocol. A radio for operating: transceiver; and coupled to the transceiver and placing the radio in a first operational state, the radio Whenever direct communication with the second radio is attempted, the base station communication protocol - causing the radio to emulate at least one of the parameters; and , whenever the radio attempts to communicate with the base station, 2. A radio device comprising: control means for setting the radio into two operating states. 2. 2. The control means according to claim 1, wherein the control means controls communication protocol parameters of the base station. by emulating at least one of said radios and control the timing synchronization of communication messages transmitted with the second radio; A wireless device characterized by. 3. 2. The wireless device according to claim 1, wherein the wireless device is a cordless telephone, and the communication system A wireless device characterized by being a cordless telephone system. 4. 2. In claim 1, when the radio is in the first operating state, the radio sending a ball message to the radio having a unique intonation ringtone; The above information indicates that it is the radio, not the base station, that is attempting to communicate with the radio. A radio device characterized in that a second radio device can be recognized. 5. Register the first and second radios with each other so that they can communicate directly with each other. , wherein the wireless device uses a communication protocol having a predetermined set of parameters. A communication system comprising: a base station that communicates with the first and second radios using a radio channel; The registration method operates in the first wireless device; scanning for link request messages; at the second radio; When the base station sends a link request message to one of the radios, using at least one of the same communication protocol parameters used by the base station; transmitting a link request message to the first wireless device; and In the line machine, the radio information from the second radio machine is stored, and once the radio information from the first and second radio machine is stored. When two radios are registered with each other, the first and second radios communicate directly with each other. Steps to make it possible; A method characterized by comprising: 6. 6. The base station according to claim 5, wherein the base station uses predetermined communication multiplexing to and a second radio, and the base station sends a link request message to the radio. using the same communication multiplexing that the base station uses when transmitting to one of the The second wireless device is characterized in that it transmits a link request message to the first wireless device. How to do it. 7. 6. The first and second radios are both cordless telephones. A method characterized in that 8. In claim 5, the radio information from the first radio device is further transmitted to the second radio device. A method characterized in that the method comprises the step of: