MXPA98001819A - Mobile telecommunications apparatus and operating method - Google Patents

Abstract

The present invention relates to a remote unit having the ability to automatically switch from a public wall to a non-public network comprising private and residential base stations. In the preferred embodiment, the public network is characterized by cells and each cell has a unique identification signal. Initially, a first switch from a public network to a non-public network requires the user to manually trigger the switch. The remote unit stores the first identification signal transmitted by the base station from which the remote unit passed through the region covered by the non-public base station. In addition, the remote unit stores the identification signal associated with a cell of the public network prior to the current cell in which the switching occurred less than two (2) minutes from the output of the previous cell. In this way, the remote unit can adaptively learn as it traverses other possible trajectories of other cells in the region covered by the non-public base station.

Description

DEVICE OF MOBILE TETROMETER AND OPERATING METHOD The present invention relates to a mobile telecommunication apparatus which can communicate wirelessly with a plurality of base stations of a first class, in a first communication protocol, and to communicate wirelessly with at least one station of base of a second class in a second communication protocol, wherein the mobile telecommunication apparatus can automatically switch from the first communication protocol to the second communication protocol.

ANGK KUENTES OF INVENTION Public wireless communication networks such as cellular networks are well known in the art. Cellular networks provide public communication between a plurality of mobile telecommunication devices. Analogue cellular communication networks typically operate in a frequency range of 824-849 megahertz. Recently, in the United States, the Federal Communication Commission has allocated a width of REF: 26985 additional band in the frequency range of 1.9 Gigahertz to allow communication over a more limited range compared to cellular communication networks. This communication protocol is called Personal Communication Service ("PCS"). Communication over the PCS network is a different communication protocol that includes frequency, instead of being done over a cellular network. Finally, the IS-136 standard for North American Digital Cellular Communication provides public, private and residential base stations. As discussed in the following, private and residential base stations should be collectively referred to simply as "non-public" base stations. The standard sketch therefore considers a mobile station that has the ability to communicate with a public communication network and with the same mobile telecommunication device is able to communicate over a non-public network with non-public base stations. The present invention relates to a mobile telecommunication apparatus and to a method for communicating between a first wireless communication network operating in a first protocol, and automatically switching to communicate wirelessly with a second communication network in a second protocol. As described, the mobile telecommunication apparatus of the present invention may increase the IS-136 standard or may also operate between the conventional cellular network and the PCS networks or any other combination of two wireless networks. The difficulty with the design of a mobile telecommunication device that can switch from a communication network to another communication network is that the mobile telecommunication device must be able to automatically know when to switch. Clearly, one solution, although undesirable, is for the user to activate the mobile telecommunication device to switch from one wireless network to another wireless network. However, this manual intervention is clearly undesirable. Another method is for the mobile telecommunication device to constantly initiate communication with both wireless networks. When there is a possibility that the mobile telecommunication apparatus is able to establish communication with a second wireless network, then switching would occur. This is clearly undesirable because energy is wasted. Mobile telecommunication devices, due to their mobile nature, are limited in terms of portable power capacity. An additional problem is that the non-public base station and its associated coverage region can be located in the middle of several different cells of a public network, so that the path that the non-public base station performs does not always pass through the same cells of a public network. Therefore, there is a need for a solution to the above problem.

BRIEF DESCRIPTION OF THE INVENTION In the present invention, a mobile telecommunication apparatus can communicate wirelessly with a plurality of base stations of a first class in a first communication protocol and can communicate wirelessly with at least one base station of a second class in a second communication protocol. Each of the plurality of base stations of the first class and of the base station of the second class transmits and receives wireless signals to and from a respective region with a region of a base station of the first class superimposed on a region of the base station of the second class. Each of the plurality of base stations of the first class transmits a distinctive identification signal, which is highly probable, but is not guaranteed to be, different from the identification signals of another particular base station of the first class. The mobile telecommunication apparatus has a means for storing a first identification signal generated by one of the base stations of the first class. The apparatus further has a means for receiving each of the identification signals in the first protocol from each of the plurality of base stations of the first class insofar as the mobile telecommunication apparatus travels through the respective regions of the plurality of base stations of the first class. Finally, the apparatus has a means for comparing the received identification signal with the first stored identification signal and initiating communication in the second communication protocol in the case of a match.

BRIEF DESCRIPTION OF DRAWINGS Figure 1 is a block level diagram of a remote wireless communication unit of the present invention. Fig. 2 is a block level diagram of the signal flow path when the wireless communication unit shown in Fig. 1 is operating in the analog mode. Figure 3 is a block level diagram of the signal flow path when the wireless communication unit shown in Figure 1 is operating in a digital mode. Figure 4 is a detailed block level diagram of an RF unit portion of the communication unit shown in Figure 1. Figure 5 is a detailed block level diagram of the analog front end portion of the communication unit shown in Figure 1. Figure 6 is a flow chart showing the operation of the programming elements used in the DSP / PSP modem decoder of the communication unit shown in Figure 1, when the DSP / PSP decoder modem is operating in the receive mode and has two modes of operation: synchronized acquisition mode and stable state mode. Figure 7 is a functional block diagram of the DSP / PSP modem decoder with its programming elements, operating in the synchronized acquisition mode. Figure 8 is a functional block diagram of the DSP / PSP modem decoder with its programming elements, operating in steady state mode. Figure 9 is a detailed functional block diagram of the synchronization recovery function during the steady state mode shown in Figure 8. Figure 10 is a detailed functional block diagram of the DQPSK receiver function during the mode of steady state shown in Figure 8. Figure 11 is a synchronization diagram of the communication protocol between similar units of Figure 1, when operating in a digital mode. Figure 12 is a topographic view of the remote wireless communication unit of the present invention, which communicates in a "public" mode as it approaches a "non-public" PBS base unit that switches to communicate with the PBS unit. Figure 13 is a functional diagram of detailed programming elements of the controller portion of the wireless communication unit of Figure 1 operating in the method of the present invention.

DESCRIPTION PETAT-COVER OF WS DRAWINGS With reference to Figure 1, a schematic block level diagram of a mobile communication unit 10 of the present invention is shown. In the preferred embodiment, the unit 10 can communicate wirelessly with a "public" carrier, a "private" carrier and a "residential" carrier in accordance with the IS-136 standard. For purposes of this discussion, then, the "private" mode and the "residential" mode will be collectively referred to as the "non-public" mode. However, it must be recognized that the apparatus and method of the present invention is not simply limited to the implementation of the IS-136 standard. The communication unit 10 comprises an antenna 12 which receives the wireless RF (radio frequency) signal. The RF signal is then processed by either a first RF processing unit 14a or a second RF processing unit 14b. From either the first or second RF processing unit 14 (a or b), the signal then passes to a baseband processor 20 through a switch 13. The switch 13 may be a MUX or a pair of transmitters MOS of type N and P or any other well-known electronic switch. The baseband processor 20 comprises an AFE (analog front end) 22, which receives the RF signal. The signal of the unit. AFE 22 is then received by a DSP / PSP decoder modem 24. The decoder DSP / PSP modem signal 24 is received by a VSELP DSP 26. An FPGA (field programmable gate array) 28 communicates with the DSP / PSP modem decoder 24 and the VSELP DSP 26. The FPGA 28 also communicates with an audio encoder-decoder 30. In addition, the FPGA 28 is connected to a controller 32. Finally, the audio codec-decoder 30 is connected to a conventional loudspeaker and microphone. As discussed previously, the communication unit 10, in the preferred embodiment, implements the IS-136 standard. Therefore, the communication unit 10 can also process both analog wireless signals as well as digitally encoded wireless signals. In general, the components identified above operate in the following manner: The RF processing unit 14 (a or b) receives the analog or digitally encoded RF signal and converts it into a band-based signal for further processing by the processor 20 of base of band. When operating in digital mode, the RF processing unit 14 also demodulates the received IF signal to produce the analog signals I, Q. The AFE unit 22 implements the analog-to-digital and digital-to-analog conversions with associated filtering functions for the I / Q signals. In addition, it provides for four (one unused) channel D / A converters for RF control. It also has an A / D for RSSI measurement (signal strength indicator received). The DSP / PSP modem decoder 24 in the preferred embodiment is a digital signal processor which is encoded ROM (TMS 320c51) which implements the analog mode processing, the modem functions in the digital mode, as well as the control functions error code FACCH (fast access control channel) / SACCH (slow access control channel). The FACCH / SACCH is defined by the IS-136 standard and is well known in the art. The DSP / PSP decoder modem 24 is interconnected with the 28 FPGA I / O decoder via serial port. Through FPGA 28, the FPGA 28 then communicates with the controller 32. The DSP / PSP decoder modem 24 also maintains the time division multiplexing (TDM) common link for communication with the VSELP DSP processor 26 and the encoder / audio decoder 30 when operating in analog mode. The DSP / PSP modem decoder 24 communicates with the RF processor 14 (aob) through the AFE 22 and through the switch 13. The VSELP DSP 26 is also a ROM-encoded DSP (TMS 320C51) which implements the functions of encoding / decoding VSELP, which is a speech compression algorithm. In addition, it performs the error control functions associated with the speech and echo cancellation box. Finally, it communicates with the DSP / PSP modem decoder 24 via the TDM port and is deactivated during the analog operation mode.

The audio encoder-decoder 30 implements the speech conversion from A to D and from D to A and the associated filtering. It interconnects directly with the speaker and with the microphone (not shown). Speech samples are exchanged with the DSP 24 / PSP decoder modem through the TDM and TDM port to the pulse code modulation (PCM) conversion circuit in the FPGA I / O decoder 28 during the analog operation mode. In addition, during the digital operation mode, the audio codec-decoder 30 is interconnected with VSELP DSP 26 via the PCM common link. The FPGA I / O decoder 28 consists of a first FPGAl 28a, a second FPGA2 28d and - n PAL (programmable array logic - not shown) for 1/0 address decoding. The first FPGAl 28a includes synchronization generation circuits, wideband data demodulator, synchronization control interface and bandstand test interface. The second FPGA2 28b includes an interface (UPIF) for interconnection with the controller 32. In addition, it communicates with the audio codec-decoder 30 and the VSELP DSP 26 through the PCM port and has TDM / PCM conversion circuits. Finally, the second FPGA2 28b has a sampling clock (interrupt control).

The controller 32 is a microprocessor and has an associated memory 31. Alternatively, the controller 32 and the memory 31 can be integrated into a microcontroller with an internal memory. The controller 32 controls the switching 13 and the transistors 15a and 15b which supply power to the first and second RF units (14a and 14b) respectively. With reference to Figure 2, the signal flow for the communication unit 10 when operating in the analog mode is shown. As you can see, when operating in analog mode, the VSELP DSP 26 is completely "off". The analog wireless signal is received by the RF unit 14 and is supplied to the unit 22 AFE. From the 22 AFE unit, the signal is supplied to the DSP / PSP modem decoder 24. The DSP 24 / PSP decoder modem through its TDM port communicates with the second FPGA2 28b. From the PCM port of the second FPGA2 28b, the second FPGA2 28b communicates with the encoder-decoder 30. With reference to FIG. 3, a block level diagram of the signal flow is shown when the communication unit 10 operates in the digital mode. In this mode, the VSELP DSP 26 is actively involved in the processing of the digitally encoded received signal. With reference to Figure 11, a synchronization diagram of a digitally encoded signal is shown when the communication unit 10 operates in digital mode, particularly implementing the IS-136 standard. The communication between the base unit and a mobile unit is divided into a plurality of frames, designated as Fl, F2, etc., and each frame lasts 20 msec. In the digital operation mode, each 20 msec frame is further divided into a plurality of time slots, shown as TI, T2 and T3. Using the voice compression capability as performed by the VSELP 26 processor, at full speed of 8 kbits / sec, for the same frame and at the same frequency, in digital mode, the base unit can be used to communicate with three units different mobile Further, when the VSELP DSP 26 is operating at half the compression rate, i.e. 4 kbits per second, communication between the base unit and a plurality of mobile units can occur using a frame of 40 msec and each frame dividing into six different time intervals or serving six users. Each time slot Tn can accommodate the transmission of 162 QPSK or 324 bit symbols. The base unit and the mobile unit 10 communicate on separate frequency channels so that a full duplex transmission is carried out. The transmission protocol from the base unit to the mobile unit is shown and designated as f (by the word forward). The transmission protocol from the mobile unit to the base unit is shown and designated as r (by the word reverse). In the forward protocol, the IS-136 standard indicates that the digitally coded signal begins with 14 synchronization signal symbols followed by 148 data signal symbols, with six DVCC symbols (one marker signal) located in the measured part of the data field between the symbols 85-91. Therefore, within each forward time interval, the transmission of 162 symbols includes synchronization and data. With reference to Figure 4, a detailed block level diagram of the RF processing unit 14 is shown. The RF processing unit 14 receives the signal from the antenna 12 through a duplexer. The received signal is supplied to a RF + IF stage 72. The RF + IF stage 72, as is well known in the art, has an RF filter, a low noise amplifier, which serves to filter and amplify the received signal, and an RF to IF converter to convert the RF signal received in an intermediate frequency signal. The conversion is based on a frequency signal difference generated by an RX frequency synthesizer 74. The frequency selected for the RX frequency synthesizer 74 is based on a signal supplied from a temperature compensated crystal oscillator 70, which passes through an appropriate multiplier 78. The output of the RF + IF stage 72 is then supplied to an I / Q amplifier and demodulator 76 whose gain is selected by an automatic gain control AGC signal. The outputs of the 76 I / Q amplifier + demodulator are the analog I and analog Q signals. In the transmission mode, the RF processing unit 14 comprises similar components as in the above. The analog I and analog Q signals are supplied to an 86 I / Q modulator, which modulates the analog signals I, Q in an IF carrier signal. The output of the IQ modulator 86 is then supplied to a step 82 RF + IF. The stage 82 RF + IF converts the output of the I / Q modulator 86 upwards in an RF signal for transmission by the antenna 12. The frequency for converting from the intermediate frequency to the RF frequency is controlled by the TX frequency synthesizer 84. . The TX frequency synthesizer 84 also receives the output of the temperature compensated crystal oscillator 70 multiplied by an appropriate multiplier 88. With reference to Figure 5, a detailed block level diagram of the unit 22 AFE is shown. The unit 22 AFE comprises a first LPF (low pass filter) 91. The first LPF 91 receives the analog I / Q signals from the RF unit 14. The output of the LPF 91 is then supplied to a converter 90 A to D from which the digital signals Rxl and digital RxQ are produced. The converter 90 A to D also receives a clock signal from the clock 92. The clock 9-2 is set by a sample base adjustment signal (which will be described later). The unit 22 AFE also comprises a converter 118 D to A, the converter 118 D to A receives the transmission of the digital signals I and Q (Tx I / Q) and converts them into Tx I / Q analog signals. The converter 118 D to A also receives the clock signal from the clock 92. The analog signals Tx I / Q are then supplied to the second LPF 117 and subsequently are supplied as analog I / Q Tx signals and are provided to the RF unit 14 . The AFE unit 22 also comprises a BDD (broadband data demodulator) 119. From the WBDD 119, the wideband data signal is produced. The broadband data signal demodulator is an analog control channel. It is described herein solely because the IS-136 standard requires that the communication unit 10 be able to handle both analogue and digital communication. It is not used during digital communication. The 22 AFE unit also comprises a 93 D to A converter which receives the control signals of Tx_power, AFC and AGC. These digital signals are converted into analog signals and are supplied to the RF unit 14 to control the RF unit 14. Finally, the AFE unit 22 receives the RSSI signal (signal strength received) and digitizes it by the converter 95 A to D. With reference to figure 6, a flow diagram of the operation of the programming elements is shown. used in the DSP modem 24, when the DSP modem 24 is operating in the reception mode. When operating in the receive mode, the DSP modem 24 has two modes of operation: a synchronized acquisition mode and a stable state mode. In the synchronized acquisition mode, the operation occurs at the beginning of each communication transfer. Once the communication has been established, the programming elements proceed to the stable state mode. There, the operation occurs once in each frame or once every 20 milliseconds. In addition, during the steady state, the DSP modem 24 initially performs a synchronization recovery operation 42 which is shown in FIG. 9 in which it will be explained in more detail. After the synchronization recovery operation 42, the DSP / PSP decoder modem 24 operates on the signal shown in the form of a block level diagram in FIG. 10 and will be discussed in more detail later.

Referring to Figure 7, a detailed functional block diagram of the synchronization acquisition operation mode for the DSP 24 / PSP modem decoder is shown. The digital I / Q signals received from the unit 22 AFE are supplied to a normalizing circuit 96. The normalizing circuit 96 serves to normalize the magnitude or amplitude of the digitized I, Q signals of the converter 90 A to D. From the normalizing circuit 96, the digitally encoded signal is then stored in a storage unit 98, which is just a buffer. As will be explained in the following, storage 98 stores at least 15 symbols (or 30 samples) which is the length of the synchronization signal portion of the digitized signal. The stored signals are then supplied to a first filter bank 100 paired. Each of the filters in the first bank 100 is adapted to receive the digital signal from the storage 98 and to filter this digital signal through a frequency range different from each other. Therefore, the output of the first paired filter bank 100 is a plurality of filtered digital signals. The plurality of filtered digital signals are supplied to a plurality of circuit 102 of first magnitude. Each of the plurality of circuits 102 of first magnitude determines the magnitude of the filtered digital signal of the first filter bank 100 paired. The output of the circuits 102 of first magnitude is another additional plurality of digital signals which are supplied to a first detector circuit 106 of maximum and threshold. The output of the first detector circuit 106 of maximum and threshold serves to detect the filtered digital signal having the maximum magnitude. In addition, the first maximum and threshold circuit 106 selects the matched filter of the first paired filter bank 100 that generates the signal having the maximum output. The output of the first maximum and threshold circuit 106 is supplied with a second bank of paired filters 108. Each of the banks in the second filter bank 108 paired has a fine frequency deviation with each other and has filter coefficients different from each other. The output of the second paired filter bank 108 is a plurality of fine filtered digital signals which are supplied to a second magnitude circuit 110. The second magnitude circuit 110, similar to the first magnitude circuit 102, comprises a plurality of circuits, each of which receives a fine filtered digital signal and determines the amplitude or magnitude thereof. The output of the second magnitude circuit 110 is a plurality of signals which are supplied to a second detector circuit 112 of maximum and threshold. The second maximum and threshold detector 112 selects the digital signal having the maximum amplitude as the output thereof. In addition, the second circuit 112 of maximum and amplitude selects the filter of the second bank of paired filters 102, producing that output. Finally, the output of the second maximum and threshold circuit 112 is a signal deviated from the initial carrier frequency to correct the carrier frequency to an AFC (automatic frequency control), and a time-slot position signal. The time slot position signal is used internally to control the start and stop of each subsequent frame. With reference to Figure 8, a block level functional diagram of the DSP / PSP modem decoder 24 operation with the programming elements therein is shown when operating in steady state mode. In the steady state mode, the DSP 24 / PSP decoder mode performs the SQRC filtering function 42 and 50 (for receiving and transmitting) and the synchronization recovery 42 (for receiving), the modulation 44 and 52 DQPSK (again for receive and transmit, respectively) and the intercalation / deinterleaving of frames 46 and 54 (to receive and transmit, respectively), and FACCH decoding and coding 48 and 56 (to receive and transmit, respectively). In addition, VSELP DSP 26 performs decoding and coding 62 and 66 of channel (to receive and transmit, respectively) and decoding and encoding 64 and 68 of speech (to receive and transmit, respectively). Referring to Figure 9, a detailed block level functional diagram of the synchronization recovery function 42 performed by the DSP 24 / PSP modem decoder is shown when operating in the steady state mode. The Rx I / Q signals of the second maximum and threshold detector circuit 112 are supplied to an interpolator 114 1: 4. The output of the interpolator 114 is then supplied to a third paired filter 116. Paired filter 116 also receives the stored synchronization signal from a storage position 104. The paired filter 116 is a unique filter and matches each input sample symbol with the stored synchronization signal of the storage position 104. After each match, the input signal is deflected by T / 8, or by an input sample and then again matched to the synchronization signal of the storage position 104. Therefore, the output of the varied filter 116 is a signal that operates at a speed of T / 8. The quality of the matched filter 116 is then supplied to a peak detector 118. The peak detector 118 receives the plurality of paired filter outputs 116, which are supplied thereto at a speed T / 8, and determines the output having the highest peak value. The output of the peak detector 118 is the imax value, the use in which it will be discussed later. The output of the peak detector 118 is then supplied to a second second order phase lock circuit 152. The second order phase interlocking circuit 152 has an internal variable AVG-POS, the use of which will be described later in greater detail. The output of the second order phase lock circuit 152 is the sampling phase adjustment signal which is supplied to the clock 92 of the AFE 22 shown in figure 5. The digital signals received Rx I / Q at the speed T / 2 are also supplied to the 150 SQRC filter bank. The output of the second order PLL 152 is used to select the appropriate SQRC filter from the 150 SQRC filter bank. The output of the filter bank 150 SQRC is then supplied to the receiver 44 DQPSK. The second order PLL 152 output is the Avg-pos signal (n + l). It is supplied to unit 22 AFE and is adjusted once each frame during the empty period. The filter coefficient of each, one of the filter bank 150 SQRC is tuned to a different sampling phase adjustment. Therefore, the second order PLL output 152 selects one of the coefficient filters of the filter bank 150 SQRC. With reference to Figure 10, a detailed block level diagram of a position of the receiver DQPCK 44 is shown. The receiver 44 DQPSK receives each symbol as the output of the synchronization recovery function 42. The digital Rx I / Q symbols are supplied to a preprocessing unit 121 which generates the control signals: speed estimation, energy calculation and CTRL. The CTRL signal controls the 44 DQPSK receiver in its two modes of operation. In one mode, each symbol of the synchronization recovery output 42 is supplied to a fine total pass filter 120. From the fine total pitch filter 120, each symbol signal is supplied to a differential detector 122. From the differential detector 122, the symbol signal is then supplied to the phase splitter 126 and a tangent arc processor 128. In another mode of operation, each symbol of the synchronization recovery function 42 is supplied to an equalizer 124. The equalizer 124 operates on all of the symbols received during the allocated time slot. After the equalizer 124 has performed its operation (which will be discussed later), each symbol of the equalizer 124 is output, one at a time. Each equalizer symbol signal 124 is also supplied to the phase splitter 126 and at the same time to the arctangent processor 128. Each of the symbol signals of the equalizer 124 or differential detector 122 received simultaneously by the phase splitter 126 and the arctangent processor 128. Phase divider 126 operates before the symbol signal by quantifying the input phase at one of the plurality of predetermined constellation points (i.e., 45 °, 135 °, 225 °, 315 °) and generates the phase signal. Arctangent processor 128 receives the same symbol signal and serves to operate on the received symbol signal to determine the arctangent of its phase. The output of the arctangent processor 128 is the signal? of phase. The signal ? of phase and signal? of phase are supplied to a first subtracter (or adder with a negative input) 130 which generates the phase error signal (? -?). The phase error signal (? -?) Is then supplied to a first multiplier 132 in which it is multiplied by a constant g1. Subsequently, the output of the first multiplier 132 is supplied to a second adder 134 in which the output frequency signal of a previous operation in a previous symbol is stored in the storage 136. Of the second adder 134, the adjustment is subsequently generated to the frequency for the next symbol or the frequency error signal. Therefore, the frequency error signal which is generated is in accordance with: ? f (n + l) =? f (n) + gx (? (n) -? (n)); The output of the first adder 130 is also supplied to the second multiplier 138 to which the constant g2 is supplied. The output of the second multiplier 138 is then supplied to a third adder 140 to which the frequency error signal? (N) of a previous symbol is also supplied. The output of the third adder 140 is supplied to a fourth adder 142 to which the carrier signal signal f of a previous bit has been supplied and stored in the storage 144. The output of the fourth adder 142 is a carrier phase error signal and it is calculated in accordance with: f (n + l) = f (n) + g2 (? (n) -? (n)) +? f (n) With reference to Figure 12, a topographic view of a region through which the mobile unit 10 of the present invention can traverse and communicate wirelessly is shown. As previously established, in the preferred embodiment, the wireless remote unit 10 communicates with a public network, consisting of a plurality of cells, in accordance with the IS-136 standard. In the public network, as is well known in cellular technology, the remote communication unit 10 communicates with a plurality of cells as it passes from one cell to another. As shown in Figure 12, each cell, for example 160, 162, 164 and 166 has an associated public base station (PBS), which transmits and receives RF signals from its respective operating region. If a remote unit 10 is located in that region, the remote unit 10 can communicate with the public network. The cells 160, 162, 164 and 166 overlap each other to some extent as long as the remote unit 10 traverses from one region of cell to another, there must be a location in which the "transfer" of communication from one cell to another occurs. . In addition, as shown in Figure 12, according to the IS-136 standard, a non-public base station (NPBS) 170 is located at a position which is also within one or more of the cells (160, 162). , 164 or 166). The NPBS 170 also has a region 168 within which it can communicate with any wireless remote unit 10 located in that region 168. The region 168 covered by the NPBS 170 is superimposed with one or more of the cells 160, 162, 164 and 166 of the public network. Typically, the NPBS 170 is located in a building or a house when a number of cells of the public network can cover and also when the strength of the wireless signals of the public network by a part of a wall or structure can be different from the strength of the radio signal on the other side of the wall. As described so far, the remote unit 10 has the ability to automatically switch from the public network to the non-public network as it traverses cells through the public network in a region encompassed by the non-public network. However, a problem can be observed with reference to Figure 12 in that the path through which the remote unit 10 traverses the public cells to reach the non-public base station 170 may vary from one occasion to another. As shown in Figure 12, if the remote unit 10 traverses the path marked "A", as it passes through cell 164 and 160 of the public network before entering the region 168 covered by the NPBS 170. If the remote unit 10 traverses the path marked "B", would pass through the cell 162 of the public network before reaching the region 168 covered by the NPBS 170. Finally, with respect to the path "C", the unit 10 remote would pass through cell 166 and cell 162 of the public network before reaching region 168 of station 170 of non-public base. Therefore, the remote unit 10 must take into account the totality of possible variations of the different paths when moving from a cell of the public network to a region of the non-public base station. According to the IS-136 standard, each of the cells of the public network is characterized by a public service profile identification ("PSP") signal. For an analog cellular network, the PSP potentially consists of the analog control channel number and the digital color code number. For a digital cellular network, the PSP preferably consists of the digital control channel number and the digital verification color code number. To further reduce the possibility of the PSP of the public network being confused with an identification signal of the NPBS 170, the PSP may consist of the above plus an ID number system, which is a characteristic signal of a cellular network , and it is well known in the art. Therefore, with the PSP signal, the remote unit 10 can identify the particular cell of the public network in which it traverses from the other public cells and differentiate a public cell from a region of a non-public base station. In the method and apparatus of the present invention, the DPS modem 24 also serves as a PSP decoder. Therefore, the DSP / PSP modem decoder 24 recognizes and decodes the signal of, for example, cell 170 on the assumption that it presents a PSP = "1", when the remote unit 10 enters the cellular region 160 for the first time and remains in region 160. The PSP identification signal is then supplied to the 28 I / O FPGA decoder which is then supplied to the controller 32. The controller 32 stores the various PSP signals decoded by the DSP / PSP modem 24 decoder in its memory. 31 associated. The specific mechanism of the programming elements that is contained in the DSP / PSP modem decoder 24 that is used to automatically switch control communication from a public network to a non-public network is shown in Figure 13. Initially, for example, if the user traverses along the trajectory "A" and since the remote unit 10 has never been "taught" to recognize the non-public base station 170, the first time the switch from the public network to the non-public network, this switching must be initiated by the user. Assuming that the user traverses the path identified as "A", the switching occurs when the user enters cell 160 which has a PSP = "1" and enters the region 168 covered by the NPBS 170. If the switching is successful, the controller 32 stores in the memory 31, PSP = "1" as the identification signal of the cell from which the successful switching occurred. In addition, the controller 32 measures the difference in time between the time when the switching occurred and the moment when the remote unit 10 first enters the cell 160. The clock signals from the clock 92 are measured by the controller 32. In the preferred embodiment, if the difference in time between the time when the remote unit 10 entered the first cell 160 for the first time and when the switching is presented is less than two (2) minutes, then the PSP of the cell previous, ie PSP = 3 of cell 164, is also stored in memory 31. Therefore, assuming that it requires less than two (2) minutes for remote unit 10 to enter cell 160 for the first time until commutation has occurred along path "A" then memory 31 will store PSP = "1" and PSP = "3". In a subsequent presentation, if the remote unit 10 traverses along the path "B", the remote unit 10 will first enter the cell 162 that has the PSP = "2". Although a portion of cell 162 is covered by the transmission region of NPBS 170, since PSP = "2" is not a PSP recognized for switching and stored in memory 31, switching does not occur. However, upon entering the cell 160 having PSP = "1" the controller 32 recognizes that the PSP = "1" stored in the memory 31 matches. The remote unit 10 attempts to initiate the switching. Since the remote unit 10 should already be in the region 168 covered by the NPBS 170, the switching would occur almost immediately. Since it requires less than two (2) minutes for the remote unit 10 to traverse the path "B" when it first enters cell 160 until the switching occurs when PSP = "2" (the PSP of a cell 162). previous) would also be stored in memory 31. Finally, in a third example, if the remote unit traverses path "C" it would first enter cell 166 that has PSP = "4". Since PSP = "4" does not match any of the PSPs stored in the memory 31, the controller 32 would not attempt to initiate the switching.After the remote unit 10 enters the cell 162 having PSP = "2", the controller 32 would find a match with one of the PSPs stored in memory 31. Then it would initiate a switching attempt, however, because the position in which the remote unit enters cell 162 is not covered by region 168 of NPBS 170, switching would not occur immediately, instead, unit 10 would continue trying to initiate switching until remote unit 10 will enter region 168 that overlaps cell 162. At this point, time and localization, switching would occur successfully, assuming that it requires less than two minutes from the time when the remote unit 10 first enters cell 162 until the switching occurs, the PSP (= 4) of the pre-cell via 166 would also be stored in the memory 31. From the foregoing, it can be seen that with the apparatus and method of the present invention, the remote unit 10 has the ability to "learn" the identity of the public cells in or near from the NPBS region. When switching is initiated, the controller 32 sends a switching signal to the switch 13 whereby it switches the signal connection from, for example, RF 14a to the base unit 20 to RF 14b to the baseband processor 20. In addition, the switching signal is sent to two transistors 15a and 15b, which suspend the power for RF 14a and supply power for RF 14b. Each of the RF units 14a and 14b can transmit and receive radio wave signals at different frequencies or different protocols. If the RF unit 14b does not receive RF signals from the NPBS 170, then the controller 32 will send a switching signal to return the communication to the public network. Subsequently, periodically, in the order of once per several seconds, the controller 32 will attempt to initiate a switchback again by generating the switching signal again. If after two (2) minutes of trying the switching is not occurring, then the previous PSP is purged from memory 31. Thus, for example, if PSP = 1 is stored in memory 31, and remote unit 10 goes through the trajectory "D" and the amount of time in which the unit 10 is in the cell 166 is greater than two minutes, without switching being present, then PSP = 1 will be suppressed from the memory 31. In addition, to expedite the verification of a PSP of a current cell, with the PSPs stored in the memory 31, the PSPs stored in the memory 31 can be classified in order of presentation frequency. Therefore, if PSP = "1" occurs more frequently, then it is classified first. Upon receiving a PSP from a cell, the controller 32 must verify with the memory 31 to determine if there is a match with the PSP ranked first. The order of frequency ensures that the cell that occurs most frequently from which the commutation has occurred in the past will be the one that is first tested. Of course, additionally the PSPs can also be stored in the memory 31 based on the classification of the most recent or recent presentation of the switching. Although the embodiments shown in Figure 1 describe two separate RF units (14a and 14b) with each of the RF units shown in greater detail in Figure 4, it will be appreciated by those familiar with the art that many of the components of the RF unit 14a and 14b are common and that those common components do not need to be duplicated in RF unit 14a and RF unit 14b. Finally, of course, the two (2) minute time period, as discussed herein, was arbitrarily chosen, and the invention is not limited to such a period of time. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, property is claimed as contained in the following:

Claims (31)

1. A mobile telecommunication device for communicating wirelessly with a plurality of base stations of a first class, in a first communication protocol, and for communicating wirelessly with at least one base station of a second class, in a second communication protocol, wherein each of the plurality of base stations of the first class and the base station of the second class transmit and receive wireless signals to and from a respective region, with a region of a base station of the first class superimposed on a region of the base station of the second class, and in which each of the plurality of base stations of the first class transmits a distinctive identification signal, the device is characterized in that it comprises: means for receiving each of the distinctive identification signals in the first protocol, from each of the plurality of stations of base of the first class, as the mobile telecommunication device travels through the respective regions of the plurality of base stations of the first class; a means for storing a first distinctive identification signal transmitted by a base station of the first class, and for storing a previous distinctive identification signal, the prior distinctive identification signal is a distinctive identification signal received by the device immediately before the current distinctive identification signal received, the current distinctive identification signal received is a distinctive identification signal currently received by the device; and a means for comparing the distinctive identification signal received by the device with the first stored distinctive identification signal, and attempting to initiate communication in the second communication protocol in the event of a match.

2. The device according to claim 1, characterized in that it further comprises: a synchronization means for measuring a predetermined period of time; and wherein the storage means purges the previous distinctive identification signal in case the device does not receive the current distinctive identification signal within a period of time at least equal to the predetermined time period.

3. The device according to claim 2, characterized in that the storage means further stores a second distinctive identification signal, the second distinctive identification signal transmitted by a base station of the first class, whose associated region is superimposed on the region of a base station of the first class, and wherein the comparing means additionally comprises: means for comparing the current distinctive identification signal with the first distinctive identification signal and for comparing the previous distinctive identification signal with the second distinctive identification signal, and in the case of a coincidence in any of the comparisons, try to initiate communication in the second communication protocol.

4. The device according to claim 1, characterized in that the first communication protocol is in a first frequency.

5. The device according to claim 1, characterized in that the second communication protocol is at a second frequency, different from the first frequency.

6. The device according to claim 1, characterized in that the plurality of base stations of the first class comprises a public carrier communication network.

7. The device according to claim 6, characterized in that the base station of the second class comprises a non-public communication network.

8. The device according to claim 1, characterized in that the region of the base station of the second class overlaps with a plurality of regions of base stations of the first class.

9. The device according to claim 8, characterized in that the storage means additionally stores a second distinctive identification signal, the second distinctive identification signal transmitted by another base station of the ficlass, whose associated region is superimposed on the region of the base station of the second class.

10. The device according to claim 9, characterized in that the comparison means further compares the distinctive identification signal received by the device with the second distinctive stored identification signal and attempts to initiate communication with the base station of the second class in the case of a coincidence.

11. A method for changing the wireless communication between a mobile unit and a fibase station of a plurality of base stations of the ficlass, in a ficommunication protocol, and between the mobile unit and a base station of a second class in a second communication protocol, wherein each of the plurality of base stations of the ficlass and the base station of the second class transmit and receive wireless signals to and from a respective region, with the region of the fistation of base of the ficlass overlaying the region of the base station of the second class, and wherein each of the plurality of base stations of the ficlass transmits a distinctive identification signal, the method is characterized in that it comprises: storing by the mobile unit, by activating the user, a fidistinctive identification signal by the fibase station of the ficlass; receiving by the mobile unit each of the distinctive identification signals in the ficommunication protocol, from each of the plurality of base stations of the ficlass, to the extent that the mobile unit traverses through the respective regions of the plurality of base stations of the ficlass; storing, by the mobile unit, a prior distinctive identification signal, the prior distinguishing identification signal is a distinctive identification signal received by the mobile unit immediately before the current distinctive identification signal received, the current distinctive identification signal is a distinctive identification signal currently received by the mobile unit; and comparing the distinctive identification signal received by the mobile unit with the fistored distinctive identification signal and attempting to initiate communication in the second communication protocol in the case of a match.

12. The method according to claim 11, characterized in that it further comprises: measuring a predetermined period of time; and purging the prior distinctive identification signal in the case in which the mobile unit does not receive the current distinctive identification signal within at least a period of time equal to the predetermined time period.

13. The method according to claim 12, characterized in that it further comprises: storing a second distinctive identification signal, the second distinctive identification signal transmitted by a base station of the ficlass, whose associated region overlaps the region of the fibase station of the ficlass; comparing the current distinctive identification signal with the fidistinctive identification signal, and in the case of a match; comparing the previous distinctive identification signal with the second distinctive identification signal; and attempt to initiate communication in the second communication protocol, in the case of a match in any of the comparison stages.

14. The method according to claim 11, characterized in that the ficommunication protocol is in a fifrequency.

15. The method according to claim 11, characterized in that the second communication protocol is at a second frequency, different from the fifrequency.

16. The method according to claim 11, characterized in that the plurality of base stations of the first class comprises a public carrier communication network.

17. The method according to claim 11, characterized in that the base station of the second class comprises a non-public communication network.

18. The method according to claim 11, characterized in that the region of the base station of the second class overlaps with a plurality of regions of base stations of the first class.

19. The method according to claim 18, characterized in that the storage stage further stores a second distinctive identification signal, the second distinctive identification signal transmitted by a second base station of a first class, whose associated region overlaps a region. of the base station of the second class.

20. The method according to claim 19, characterized in that the comparison step further compares the distinctive identification signal received by the mobile unit with the second stored distinctive identification signal, and attempts to initiate communication with the base station of the second class in the case of a coincidence.

21. The method according to claim 20, characterized in that it further comprises the step of: classifying the first and second distinctive identification signals stored based on the frequency of presentation.

22. The method according to claim 20, characterized in that it further comprises the step of: classifying the first and second distinctive identification signals stored based on the most recent presentation.

23. The method according to claim 22, characterized in that it further comprises the step of: determining a predetermined period of time; and purging a distinctive identification signal stored in the mobile unit in the absence of a match within a predetermined period of time.

24. A method for operating a portable communication device for switching communication between the apparatus and two wireless networks, each of the networks transmits a characteristic signal, the method is characterized in that it comprises: verifying the characteristic signals transmitted by one of the two wireless networks; store signals characteristic of a network, when a user activates the communication switching from one network to another of the two wireless networks; communicate wirelessly with a network, while checking the characteristic signals of it; storing a prior distinctive identification signal, the prior distinguishing identification signal is a distinctive identification signal verified by the portable communication device before the current distinctive identification signal is verified; compare the verified characteristic signals while communicating with a network with the characteristic signals stored; and attempt to initiate communication automatically with another network in the case of a match in the comparison stage.

25. The method according to claim 24, characterized in that it further comprises: measuring a predetermined period of time; and purging the prior distinctive identification signal in the event that the portable communication apparatus does not receive the current distinctive identification signal within a period of time at least equal to the predetermined time period.

26. The method according to claim 24, characterized in that the communication with the first wireless network is at a first frequency.

27. The method according to claim 26, characterized in that the communication with the second wireless network is at a second frequency, different from the first frequency.

28. The method according to claim 24, characterized in that the first wireless network is a public carrier communication network comprising a plurality of base stations, each base station communicates with a cell.

29. The method according to claim 24, characterized in that the second wireless network is a non-public communication network comprising a base station communicating within a region.

30. The method according to claim 28, characterized in that a plurality of cells of the first wireless network overlap in the region of the second wireless network.

31. The method according to claim 30, characterized in that each of the plurality of base stations of the first wireless network transmits a distinctive identification signal, with characteristic signals that are distinctive identification signals.