JP2002512740A - Switching system with wireless communication system and multi-directional antenna - Google Patents

Abstract

(57) [Summary] Wireless PBX systems utilize base stations distributed over a single area used for wireless telephone service. To reduce the problems associated with fading and multiple paths, a base station utilizes multiple antennas. The base station's antennas are rotatable and at least paired, so that the base station may be suspended vertically, parallel, or at some angle to the horizontal, so that the local area in which the base station is mounted may be suspended. Directivity can be easily imparted to the antenna at a position that provides favorable propagation characteristics of the antenna. Also included are systems and methods for easily changing the placement of the telephone system and the features / properties available to the user of the wireless telephone device of the system. The telephone device may include a display that may be positioned by interaction with the base station to change the interpretation given to the input received from the user.

Description

The present invention relates to a switching system comprising a wireless communication system and a multi-directional antenna. Generally relates to communication systems and methods in telephone systems, In particular, A system and method for using a portable wireless telephone integrated with a terrestrial wired telephone system. The telephone industry One is the relatively inexpensive cellular telephone: Mobile phone) service, Here 2, It has grown significantly in three years. In this service, Phone subscribers can carry, Powered by batteries, Using a handheld telephone device, A network of base stations that interface the terrestrial public telephone network with signals on the RF link; Communicate via RF link. In this system, The cellular form is usually used, A particular base station uses a particular frequency to communicate with multiple mobile phones in that "cell" Proximate base stations use different frequencies to communicate with multiple phones in the cell. If the base station is far enough from other base stations, Unless neither the base station nor the phone of one cell derives a signal of sufficient power to affect the other cells, The same frequency can be used for both cells. in this way, A non-conflicting pattern of providing telephone services in a specific area, A limited number of frequencies can be reused. of course, When a phone moves from one cell to another, To avoid communicating with non-adjacent cells using the same frequency as a different cell, Switch between phone frequencies (or "hop" to a new channel) during a call. The use of cellular telephone technology It enabled the use of many mobile phones in large areas. But, With the spread of mobile phones, The frequency (or "channel") is full. In the limited RF band used for all simultaneous phone use, Solving cellular congestion It is not always necessary to simply add additional frequencies or channels within each cell. With conventional technology, Use smaller cells, By reducing the output of the cellular device, It has been proposed to reuse frequencies closer to others. But, This solution is not entirely satisfactory. Because At greatly reduced output levels, This is because the signal to noise ratio of the communication may reach unacceptable levels in telephony. From this, Conventional technologies are office buildings, It has been proposed that part of an office building or an office complex be a cell site or a small cellular system. But, From the current congestion of cellular systems, This proposal is also generally limited in the number of mobile phones that can be accommodated. In many office environments, At the office (worker: Workers) often leave the designated workplace for a long time, Sometimes they roam around in the office when they need to work. With conventional technology, If you want to provide phone service to people walking around here and there, Automatically turn a call from one place to another, It often meant a call-call (telephone) transfer scheme. Such systems are generally Since the user requires a lot of input into the device, That was a drawback in a typical office environment. Therefore, It is desirable to use mobile or cellular technology for people in the office. In a typical office building, Add cellular phones to existing terrestrial systems, For example, a private business exchange (or "PBX") provides mobile communications, It was not enough for efficient communication. In general, The mobile phone Integrating cellular system RF communications into the public terrestrial telephone system, Do not directly integrate employee PBX, Connected to base unit. In practice, Such a solution in an office environment The two are not strongly connected, Or in any case an equal relationship, This results in two independent telephone systems. further, The external structure of the building that houses the office is It may not be practical to transmit a typical cellular RF signal to or from a base station. Employees Office buildings and parts of office buildings, Be able to walk around in certain areas, To ensure that these employees have access to the telephone system, Or the solution of making employees take advantage of the telephone system, Integrating the wireless system into the PBX. With this integration, Employees receive calls over the wireless system, No matter where employees are within the operating range of the system, It becomes possible to call directly. at the same time, Employees walking around are sitting in their own seats with wired systems, You can easily receive telephone calls (telephone) both inside and outside the office. The roaming employees, No matter where you are in the office, Advantages of all properties of PBX (for example, Dial function registered personally, Special accelerator to a limited circuit, etc.). Preferably, Wireless PBX system is easy to use, Lightweight, Includes mobile phone units with long battery life. The latter two hopes are Battery life is often directly related to battery size (or weight), In a sense, they are contradictory. Therefore, It is often important to design a portable unit that has the highest possible output efficiency. In a traditional cellular system, A particular base station has one or more control channels, And it is known to combine several or many audio channels. The control channel communicates with the control of the mobile unit, Adjust the use of audio frequencies, Typical central office functions (for example, Dial a number, Call mobile unit, Perform similar functions. When the previous audio channel in the base station is being used, The control channel is no longer needed. Because This is because the control process is not executed until one of the audio channels becomes available. In such a system, It is desirable not to waste audio channels that are not working, Without incurring additional hardware costs and additional bandwidth used by the system, To expand system capacity compared to conventional systems, Additional audio channels can be obtained. Therefore, One object of the present invention is to provide A new system and method for integrating a wireless telephone system into a private branch exchange (PBX) or similar office telephone system. Another object of the present invention is to provide It is to provide a new system and method that uses all available channels of a wireless system for voice (or data) messages. Another object of the present invention is to provide It is to provide a new system and method that uses all available channels of a wireless system for voice (or data) messages. Still another object of the present invention is to provide Without reducing the capacity of the mobile unit, It is to provide new systems and methods that reduce power consumption in such units. Another object of the present invention is to provide Without extensive telephone laying and / or much programming, It is to provide a new system and method that can be installed in an office environment. Another object of the present invention is to provide It is an object of the present invention to provide a novel system and method that offers the possibility of an integrated wireless PBX telephone using housings that can be easily mounted on existing walls and ceiling surfaces of offices. Another object of the present invention is to provide Base stations can be easily added to the system (or reset after power outage) And a new communication system and method in a wireless system that can be brought online without much programming. Another object of the present invention is to provide It is to provide a novel system and method for accurately and efficiently communicating between multiple wireless telephones and multiple base stations. These and other objects and advantages of the present invention are: claim, Attached drawings, Upon perusal of the detailed description of the preferred embodiment below and It will be readily apparent to one skilled in the art to which the invention pertains. FIG. FIG. 2 is a simplified functional block diagram illustrating an embodiment of the system of the present invention. FIG. FIG. 4 is a timing chart showing a relationship between a frame and a slot used in the communication system of the present invention. FIG. FIG. 4 is a timing chart showing timing of control and communication channels in a system of the related art. FIG. Control and communication channel timing, FIG. 3 is a timing chart showing timings of a reception part and a transmission part of a communication frame used in the present invention. FIG. FIG. 2 is a view inside a building showing possible locations of people and telephone base stations inside the building. FIG. In one embodiment of the present invention, FIG. 5 is a frequency allocation diagram illustrating the use of a carrier frequency. FIG. FIG. 4 is an illustration of a base station housing and multiple antennas in one aspect of the invention. FIG. FIG. 4 is a timing chart showing a frame used in a communication unit between a base station and a mobile phone according to the present invention. FIG. FIG. 4 shows an exemplary chart of the output of the correlator used in the present invention. FIG. FIG. 4 is a simplified functional block diagram illustrating another embodiment of the system of the present invention. Referring to FIG. A telephone system using the present invention Like the United States public telephone network, It may include a switch 10 connected to multiple lines or mains of a standard telephone network. Switch 10 also Over a telephone line or similar non-propagating medium, It is connected to a plurality of land phones 14. Switch 10 is connected via a Base Station Interface Unlt (“B SIU”) 16 One or more base stations 18 may be connected via base station connector 20. Each base station 18 As described below, Means for wirelessly communicating with a plurality of mobile phones 2 is included. In its operation, The switch is PBX, PABX, Operates as a standard telephone switching unit such as a key system, Functionally, Interconnect the telephone 14 to the public telephone network. Such a switch 10 A switch unit such as the unit sold by HARRIS CORPORATION as "HARRIS 20/20" may be used. Depending on the scope and complexity of the switch, Memory dialing, Call forwarding (telephone) transfer, Voice mail response and shipping, And other features common to modern telephone switches, It may have a number of features that assist the telephone user in talking. One of the functions achieved by the switch is Mapping an in-bound or extension telephone call (telephone) to the desired telephone; And providing an "outside line" to the system telephone upon request. When an intra-area call (telephone) is bound for one of the land phones 14, Switch 10 is typically Call the desired telephone via telephone line connection (telephone), Between the desired telephone 14 and the outside line receiving the call (telephone) Establish a voice communication path along the same or another telephone line connection. The telephone call (telephone) received by the switch 10 addressed to the mobile phone 22 is: It is routed to the BSIU which transmits appropriate control information to the base station currently controlling the mobile phone 22 in the following manner. When a call (telephone) is connected between the mobile phone 22 and another phone, The switch 10 operates to indicate the audio circuit to the BSIU 16; The BSIU 16 also indicates to the voice circuit the selected base station 18, Base station 18 also Information about the voice message on the voice circuit is transmitted to the desired mobile phone 22 via the wireless link 24. As we all know, The telephone audio circuit may be analog or digital. In one conventional system, The telephone line coming from the telephone network may be an analog line. In a conventional switch circuit, The switch 10 An analog voice circuit from the telephone network is routed to the terrestrial telephone 14 in an analog or digital mode. If a digital switch is used, Switch 10 converts voice information from the analog telephone network into a series of digital bits, The bits are communicated to terrestrial telephone 14 by conventional means. Communication from the digital terrestrial telephone 14 to the telephone network 12 is transmitted from the telephone 14 to the switch 10, Converted to an equivalent analog signal, Applied from the telephone network 12 to the telephone line. The present invention It is not limited to using only analog switches or only digital switches, The inventive concept disclosed here is: It can be easily completed using analog or digital switches. The present invention is not limited to the use of a PBX or similar "stand-a lone" type device, It is desirable to integrate the radiotelephone with other radiotelephones or terrestrial telephones, Applicable to any telephone system or subsystem. Therefore, The switch 10 itself is an "external" telephone network 12; Conventional means not limited to wired systems, For example, via a microwave link, You may communicate. Therefore, Even if the description of the embodiment describes a particular signal in the switch as a digital signal or an analog signal, The invention is not limited to systems with such signals, The description is merely illustrative and not restrictive. An analog telephone call (telephone) addressed to one of the mobile telephones 22 is converted into a digital form in the switch 10, It is transmitted to BSIU16. At BSIU, The digital information from the call (telephone) is combined with similar digital information from other call calls and transmitted via communication link 20 to base station 18; Handle call calls. Also, In the method described below, Base station 18 may communicate the digital information from the telephone call to the desired mobile phone. Since the current system is a telephone system, Note that there is a return path for telephone calls. that is, Simply reverse the above flow, The digital form of the voice applied to the mobile telephone 22 is provided from the telephone network 12 to an appropriate telephone line through the base station 18 and the BSIU 20. If the telephone network line is an analog line, The digital form of the return signal will be converted to analog form for application to telephone network line 12. As we all know, If your voice message is considered continuous, The digital form of such a message need not be a continuous stream of digital bits. Rather, If the digital device has enough processing power, Cluster of digital bits representing a sound signal (bundle: cluster) Before another cluster of bits is transmitted again, They may be transmitted together after a certain time. When a digital signal is converted to analog, If a series of clusters of digital bits arrives within the latency period between clusters, A user listening to the received analog signal cannot perceive the fact that the voice message was split and transmitted. The present invention takes advantage of this fact, It allows multiple mobile phones to time-share a single frequency or channel between base station 18 and mobile phone 22 simultaneously. Referring to FIG. In a communication format known as time division multiple access, Multiple mobile phones share a single frequency. As shown in FIG. A particular frequency (or carrier) may have multiple slots, The system of FIG. 2 is divided into eight. Due to the inherent synergy of base station 18 and mobile phone 22, The mobile phone is a slot that is repeatedly generated as one of the eight slots, The digital message in slot 2 can be received. In this way, The mobile phone 22 is, as shown in FIG. The digital data of the slot 2 is received. 7 slots after the end of the first slot 2, Then, the second slot 2 holding the digital data of the specific mobile phone 22 again arrives. Each slot can carry multiple digital bits of data. As long as the slot repeats at a sufficient frequency, The mobile phone 22 converts the digital format of the voice message, The message can be received sufficiently that the analog form of the message can be accurately reconstructed by digital-to-analog conversion in the mobile phone 22. The length of time that elapses before consecutive slots are received to avoid data loss is How many bits are transmitted at the same time, It depends on the voice frequency in the voice message which has a well-known relationship. As mentioned above, A typical telephone message is two-way, Therefore, Two slots are required for phone calls, One of them is the transmission of a digital signal to the mobile phone 22, The other is transmission of digital signals from the mobile phone 22. One phone call occupies only two slots in the frame, Other slots can be used simultaneously by other mobile phones 22. In general, The base station Inform mobile phone 22 which slot is being used for a particular phone call, To ensure that all of the communicating mobile phones are used at the same time (usually the signals transmitted by both are destroyed, To avoid two phones transmitting at exactly the same time), Use a specific protocol. In conventional systems, Typically, The first slot of the frame transmits voice signals from the base station to various mobile phones, It is used to control thereby. For example, Referring to FIG. The prior art 9 slot frame uses the first slot (CON) as a control slot (for transmitting control messages from the base station to the station), The next four slots for voice signals are transmitted from the base station to the mobile phone (T1, T2 T3 Sent to T4), The last four slots for voice signals are transmitted from the mobile phone to the base station (R1, R2 R3 R4). In the system of the present invention, As shown in FIG. The first slot (CON) of the frame is used as a control slot, Contrary to conventional technology, The remaining slots are For the base station transmitting the first half slot and the base station receiving the second half slot of each slot (transmitted by the mobile phone), It is divided into two half slots. Compared to the prior art, The use of the present invention has particular advantages in reducing the power consumption of mobile phones. In the prior art, When the communication part is not needed, It is known that the power supplied to the communication part of a mobile phone is reduced. Therefore, For example, in the prior art of FIG. The mobile phone has all but three slots, That is, Send, In the slot where communication within the receive and control slot is scheduled, The power to the communication part can be reduced. According to one aspect of the invention, The communication part of the mobile phone (As described below, The mobile phone of the present invention During a telephone call, the communication channel (or slot) need not be monitored, so it needs to be fully energized for only one slot. Therefore, The present invention As long as there are few slots per frame, In addition to reducing the need to increase the power of the communication circuit, While the power is off and reduced from the communication circuit Reduce periods of relatively inefficiency. As is known in prior art systems, The control channel is a communication system frame, It can be used to establish the timing of communicating control information between the base station and the mobile phone. For example, During the control channel, The base station has a specific mobile phone, To let you know which slot and frequency to use for audio data, Or on a specific phone, Data can be sent that informs how to respond to user entries on the telephone keypad. Also during the control slot, the system, During that time, A cell phone looking for an audio circuit can send the request to the audio circuit, And / or Provides a period during which base station or PBX management data or functional requests can be transmitted. Referring to FIG. The ability to continuously cover one area of the system of the present invention is illustrated on a typical floor plan of office space 50. In the office space 50, Several walls 52 divide the space into a private room 54 and a corridor 56. The base stations BS1 and BS2 are located in the office space 50, Provide a call coverage that covers it. The number and location of base stations will depend on the expected traffic and the form of space covered. The space is one floor of the building, Multiple floors of the building, Multiple buildings, And / or may be part of an external space associated with the building. If the user wants to use his mobile phone in the space covered by the system of the present invention, Enter a series of instructions on your mobile phone. By the steps described below, The mobile phone selects the base station, Thereby, Within one period of the control slot associated with the base station, The user's request for the voice circuit is communicated and transmitted to the selected base station. The base station determines which slots and frequencies are available, A message is returned to the mobile phone that has confirmed the slot and frequency to be used as the voice channel for the mobile phone. With standard signal technology, The mobile phone sends the subscriber number of the phone to be dialed, Or request other features of the telephone system. Continuing with reference to FIG. 5 by way of example, Each base station in the system may be associated with a frequency used for a control channel. When your mobile phone is looking for audio circuits or other features from the phone system, The mobile phone scans for frequencies that are known to be assigned as control channels, Which control channel signal has the highest signal strength, Signal-to-noise ratio, And / or Determine if received with other signal characteristic metrics. The control channel signal with the best characteristics is selected, The cell phone initiates contact with the base station transmitting the signal via the control channel. Regarding the office space in FIG. 5, If the base station has an available channel, Since the base station is closer to other base stations, The mobile phones PT1 and PT3 are expected to communicate with the base station 1. Otherwise, Cell phones PT1 and PT2 are expected to communicate with base station 2. Similarly, For the same reason, The mobile phone PT4 communicates with the base station 2 ( Get audio channel). The base station with which PT3 and PT5 communicate is It cannot be easily determined from the outline of the space in FIG. Although the mobile phone PT5 is physically closer to the base station 2 than the base station 1, Note that the direct path between mobile phone PT5 and base station 2 is through the wall. Wall thickness and composition, Depending on a number of factors, including the size of the door that the cell phone PT5 exits into the hallway from the room where it is, The base station 1 or the base station 2 (if available) may be the location of the mobile phone PT5. By using the selection scheme of the present invention, Assignment of mobile phones to specific base stations becomes dynamic, Note that local changes in signaling between the mobile phone and the base station are taken into account. In one embodiment of the present invention, Incoming calls and outgoing calls Mobile phones are actually handled in the same process, The only difference is that In the case of an incoming call, the "ring" signal precedes. After receiving the "ring tone" signal, In the present invention, For both incoming and outgoing calls, It may be used in mobile phones. During a call on a specific mobile phone, Mobile phone users can move around the office. When the user moves, The user sometimes moves away from the base station controlling the call. In the system of the present invention, The mobile phone monitors the quality of the communication between the mobile phone and the base station, If there is a signal drop according to the following predetermined criteria, Reselect the base station, Request that the call move to a new channel (or slot / frequency combination described below) of the base station that will best communicate with the mobile phone. For example, Referring again to FIG. The mobile phone at the designated location PT1 in a certain space It is expected that the first closest base station BS1 will be used (assuming BS1 has an available channel). If the mobile phone user moves from PT1 to PT4 during a call, When the quality of the signal between the mobile phone and the base station controlling it (eg BS1) has deteriorated sufficiently, The mobile phone looks for a new communication path. At the position selected for PT4, The mobile phone is the closest base station, It is currently expected to select BS 2, Obtain a voice channel from the newly selected base station. In the system of the present invention, The user moves the position, Just because other base stations are near and / or direct, Note that the mobile phone does not need to switch the base station. Rather, Unnecessarily flying from one channel to another (hopping: hopping) The mobile phone of the present invention As long as the quality of the voice communication is acceptable, Continue to stay at the current base station. The mobile phone Evaluate any characteristics of the communication channel between the mobile phone and the base station. In the present invention, As an assessment of signal quality, It has been found that evaluating the quality of speech, typically provided by a vocoder in a communication circuit, is efficient. Using this evaluation for hopping control Especially efficient. Because many vocoder circuits, It has already been evaluated as part of the volume control operation, So by using this, This is because the need for another circuit or processing function can be avoided. In standby mode (not an ongoing voice call) The mobile phone evaluates the signal quality based on the quality of the control channel from the base station. If the signal quality drops to a certain standard, The mobile phone switches to the control channel of another base station. This technology is Also called soft roaming, Just before the signal quality actually drops below the level that hops need, Prevent transition effects that can occur when a call is initiated or received by a mobile phone. In a newly established call situation, The mobile phone is on the communication channel Not getting enough useful call data to start the base station / frequency / slot switch exactly. By using the technology in this standby mode, The system of the present invention seeks to increase the likelihood that a mobile phone will use the best base station nearby. As long as the channel continues acceptable communication, By staying on a given audio channel, The portable unit does not need to monitor the control channel during a telephone call. Because Since the assigned slots are generated at a known repetition rate, During voice communication, The mobile unit does not The energization of the communication circuit may be stopped. At the end of the slot, The portable unit stops energizing the communication circuit, A timer can also be set to quickly re-energize the communication circuit before the assigned slot is next created. Time between slots, The mobile phone converts the digital audio data received from the forward channel (base station to mobile phone channel) from digital to analog format, Apply to the phone speaker (or earpiece) The digital information corresponding to the audio input (or the user's keypad entry) received during the time between slots is stored. When the next slot is created, The mobile phone receives the next packet of the previous channel audio data, Transmit the next packet of voice data entered by the user during the time between slots. As long as the clock circuit in the mobile phone is sufficiently synchronized with the base station clock circuit, The mobile phone Using a timing circuit, Without querying the control channel, It is possible to fly directly from one slot to the same slot in the next frame. Referring to FIG. In the system of the present invention, A slot or channel is considered a particular slot / frequency combination. In a system with 8 slots per frame, There are eight channels or communication opportunities per frame, Each "possibility" includes forward communication and reverse (cell phone to base station) communication. Inside the slot, Forward and reverse communications are carried on the same carrier frequency. Therefore, Each base station has eight slots under its control. Each slot is within one frame, Independent of other slots, Each slot can be any channel frequency used in the system. Therefore, Taking the base station 2 of the system of FIG. 6 as an example, Slot 1 (usually a control channel, (See below) may be a control channel operating at a particular frequency f6. In the system of FIG. Base station B is also performing three voice communications, One mobile phone uses frequency f13 on slot 3; Another mobile phone uses frequency f2 on slot 6, Another mobile phone uses frequency f3 on slot 7. Each slot starts at a predetermined time after the start of a frame. Therefore, The mobile phone sends the message "Slot 6, Use frequency f2 ". The mobile unit is Receiving forward audio data on frequency f2 after a predetermined time associated with slot 6 after the start of each frame; And that during the appropriate time in slot 6, the reverse data on frequency f2 should be transmitted. In the system of the present invention, In any slot of any base station, Any of the assigned frequencies may be used. Therefore, There is no frequency assignment or frequency set to a particular base station. The features of the present invention are: system, Relocation of base stations, Or it is very easy to install a new base station. further, According to this feature of the invention, The system is very flexible to meet the demands of mobile services for mobile users and the terrain of a given system. In operation, The base station monitors the channels assigned to the system, Determine available slot / frequency combinations. By tuning to each assigned frequency during an unused slot, The base station determines which slot / frequency combination is not used within that range, Assign one of the available slot / frequency combinations when a new voice channel is requested by the mobile phone. Significantly, Available slot / frequency combination data is Generated on a local basis by each base station. Because the range of base stations and mobile phones is limited, The fact that certain slot / frequency combinations are used in the system It does not necessarily mean that they cannot be used anywhere in the system. For example, Referring to the system of FIG. Base station A sends one of the mobile phones controlled by it, Can be assigned to use slot 5 and frequency f9, The same slot and frequency, It can also be used in relatively distant base station areas, such as in base station N of the system of FIG. As long as the base station and the cell phone controlled by it are far enough apart, In the system of the present invention, the frequency / slot combination can be used and reused multiple times, The system offers great potential for handling many simultaneous telephone calls. In general, The system of the present invention During the unused slot period, To determine if a slot / frequency combination is available, System monitoring may be used. If the base station cannot detect that a particular slot / frequency is in use, Even if a relatively distant mobile phone and base station use the same slot / frequency, The slot / frequency is determined to be "usable". In this system, Even if a particular base station Even if you think you can use it far enough from a particular slot / frequency combination, Cell phones controlled by a base station may be subject to interference from "remote" use of the same slot / frequency combination. But, As mentioned above, The mobile phone monitors the quality of the voice signal communicated during the assigned slot, If such interference occurs, Initiate a hop to another frequency / slot combination of the same or another base station. In still other features of the invention, The capacity of the system to carry telephone calls is This is improved by using a disappearing control channel at each base station. If all of the non-control channels are used for active phone calls, The base station can freely assign the control channel as a voice channel. As mentioned above, Once a telephone call has been established on one slot, The mobile phone making the call does not need to use the base station's control channel anymore. All "normal" audio channels are filled, If only the control channel remains at the base station, Once the base station assigns that channel as an audio channel, As long as all channels are occupied by voice communications, There is no need for the base station to have a control channel. Within a terrain area served by a base station that has given up its control channel, Mobile phones that want new audio channels Does not automatically detect that base station as available, Select another base station that can communicate with the control channel. As mentioned above, Power reduction is an important issue in mobile phone design. In another aspect of the invention, Power is reduced when the mobile phone is in a "standby" mode. In this mode, Mainly while waiting for a new phone call or the user to make the next phone call The mobile phone is activated but no voice communication occurs. In standby mode, A mobile phone according to one aspect of the present invention includes: Do not monitor every frame of the communication, Monitor all Nth frames, After monitoring is completed, Reduce the power of communication circuits, After the N-1 th frame has passed, a timer is set to turn on the power to the communication circuit again. A series of N frames is called a "superframe". In this way, The phone "answers" the call, In a state where the call can be easily turned at the request of the user, Communication power consumption is greatly reduced. In the prior art relating to communication between a plurality of remote devices and a base station, One known problem is: All or many distant devices attempt to communicate with the base station control channel almost simultaneously, Messages collide with each other, Little or no communication with the base station is successful. In the system of the present invention, The mobile unit is Recall that an attempt is made to communicate with the base station by transmitting during a particular time after the start and after the elapse of the control channel slot. If one or more mobile phones try to send at the same time, Neither will succeed. The problem with collisions on the control channel is When all of the mobile phones re-establish contact with the base station, When the system is turned on, And immediately after reset, There are many problems. To reduce collisions on the control channel, The mobile phone of the present invention To determine which frame of the superframe is trying to contact the base station control channel, Use the number assigned to your mobile phone. The number assigned to the mobile phone may be programmed into one of the memories, May be input by a DIP switch, It may be read by a microprocessor in the phone or similar semi-permanent (or permanent) method. In the system of the present invention, The base station indicates the position of each frame in the superframe in the control channel. For example, When a superframe consists of 32 frames in a particular system, Control channel communication is Includes an indication that consecutive frames are numbered from 1 to 32. The mobile phone Usually the number of frames in the superframe, Divide the assigned number by the coefficient, During a number of frames equal to the modulus remainder, Attempt to access control channel. For example, The mobile phone In a system with 32 frames per superframe, If you were assigned the number 179, The mobile phone is in the superframe during the 19th frame (ie, 179, the coefficient is 32 and the rest is 19), Attempt to communicate with the base station. To spread control channel access attempts throughout the superframe, As long as the number is assigned, Note that each cell phone need not have a unique number. If a collision occurs on the control channel, even with the advantages of the present invention, For example, a fallback contention scheme can be used, such as the scheme used in "slotted aloha" systems. In that scheme, Each of the colliding mobile phones In hopes of eliminating or reducing further collisions due to randomness of time (randomness) Wait for a random (random) time before attempting to access the control channel. In a remote communication system, Electromagnetic signals transmitted from one device often do not go directly to the receiver, It is well known that bouncing from one object or surface to another takes various paths before being received. Bounce off the wall before the signal is received, Go through the wall, Also bouncing off other surfaces, Inside the building, Multipath is a particularly significant problem. While bouncing and at the receiving antenna, As a result of the various multipath signals combining and interfering with each other, The received signal is Normal, While various cancellations occur in the waveform, Arrived in various phases, Many copies of the original signal. To reduce the effects of multipath, In the prior art, Diversity of space and frequency (diversity: Diversity) It is known to use multiple antennas for a receiver. In many such systems, The receiver selects the antenna with the best signal, Receive a signal from that antenna, It has a logic circuit for eliminating other signals. In other prior art antenna diversity systems, Receiver circuits attempt to combine the signals that appear on the various antennas. Normal, In the prior art, The latter system has better reception, but There is a burden that the circuit becomes more complicated and the number of circuits increases. The problem with multiple paths is (Maintain power, Power levels are usually low (to allow frequent reuse) Mobile phone is not fixed in space, Often worse in mobile systems. (Usually internal to the phone, Or re-adjust the antenna to a base station (fixed outside the direction of the phone) Often, the user repositions the mobile phone during a call. further, Because users often move, The coriolis effect causes the transmitted signal. Therefore, In mobile systems, it is particularly beneficial to use antenna diversity at both the base station and the mobile phone. In another aspect of the invention, The system of the present invention uses "duality" to improve signal reception. Referring to FIG. Each base station 70 may have a plurality of antennas 72 associated with it. In each slot where the base station communicates with the mobile phone, The mobile phone first communicates with the base station. In the preamble part of the communication from the mobile phone to the base station, The mobile phone is in the preamble part, Used by the base station to test reception on each antenna, It contains a predetermined bit pattern of the signal (4 in the system of FIG. 7). The base station then uses the best antenna to receive the rest of the communication from the mobile phone. During the same slot, The base station has the opportunity to communicate the forward data to the mobile phone, This data is transmitted using the same antenna that received the data from the portable unit. The base station transmission part to the mobile phone is It follows immediately after receiving communication from the mobile phone and evaluating the best antenna to use, The preselected antenna is As it is no longer the best antenna to use between the base station and the phone, It is unlikely that the mobile station has changed its location. The base station The same antenna estimation and selection of each slot in the frame can be used. Therefore, Selecting different antennas for each of the consecutive slots that the base station uses Absolutely possible. By the inventor of the present invention, During antenna selection, It has been discovered that the antenna may be switched while measuring its signal quality. Due to the delay inherent in the switching circuit and the delay in measuring the received RF signal, After the antenna is commanded to switch outside of communication, Some time, Testing can be continued. The advantages of this technology are: There is no need to dedicate many preamble parts to the antenna diversity function, The point is that more signal data can be tested. According to another feature of the invention, Use the best antenna later in the slot for transmission to the mobile phone, By evaluating the two best antennas for the attenuation setting evaluation, The antenna selection system may select the two best antennas for a given slot. If the signals received at the two best antennas exceed a predetermined figure of merit, Another antenna can be added to the signal path during the next frame. vice versa, If the two best signals are weaker than a given advantage characteristic, The attenuation may be eliminated in the next frame. In this way, By selectively adding or removing attenuation depending on the strength of the two signals, The dynamic range of reception is increased. The use of signals from two antennas is not meant to limit the invention, If that is desirable, There is a burden that processing will increase, More signals may be used. Similarly, The benefit characteristics are individually Or to the strength of the two signals combined in the desired way, Or it is related to other characteristics of the received signal. With continued reference to FIG. The base station of the present invention has a suitable shape, It may be desirably housed in a housing 76 that is well integrated with typical office decor. The base station 70 Rotatable from a position along the side of housing 76 (as shown for antenna 72a); Or perpendicular to it (as shown for antenna 72), It includes a plurality of independently fixed antennas 74. The antenna 72 is Rotatable about axis 74 while maintaining electrical contact between the antenna and circuitry within housing 76; It may be secured to housing 76 via conventional means. Optionally, The antenna is Can rotate around one or more axes, Allowing individual alignment, such as a ball and socket arrangement (not shown), It may be secured to the housing via other conventional means. In fact, The physical fixation of the antenna As long as the electrical path is maintained between the antenna and the base station communication circuit, Not necessary. In operation, The antenna 72 of the base station 70 Enhance the communication capability of the base station 70 with the mobile phone; They can be aligned in any way. For example, In the system of the present embodiment, Base stations and mobile phones may be designed to use vertical polarization. If the base station is mounted on the ceiling, All antennas 72 provide directivity to match the system design, It may be suspended vertically. If the base station is mounted on a vertical wall, The bottom set of antennas is laid down on the housing 76 while The two upper antennas may be suspended 180 degrees relative to the vertical upper position. Similarly, The antenna is In order to adjust abnormal RF transport conditions in a terrain area near the base station 70, Such as increasing the signal processing capacity ratio to mobile phones, It can be in any position independent of housing 76. One means of achieving signaling between the mobile phone and the base station of the present invention is 1. of the present invention FIG. 8 is a timing chart showing a functional configuration of five (one-half) slots. A time slot may contain multiple bits of information, and in one embodiment of the invention 240 bits are used. The first portion of the slot includes a preamble portion that may include enough synchronization bits to allow the receiver to acquire a signal before data is received. Following the preamble may be a "unique word", i.e., a predetermined set of bits always at the same position in the slot. By using a single word at a known location in the slot, the receiver can synchronize its frame clock to the transmitter's frame clock. There may be multiple "data" bits following a single word. Depending on the type of message and on-call activity at the transmitter, the data bits may include digital voice data, command data, etc. (here typically "application" data). Finally, some type of checksum or CRC may be included to help ensure that the receiver has correctly received the message. In general, any type of known verification scheme can be used during communication. They include checksums, check bits, folding checksums, error correction bits, etc., that achieve a tradeoff between the number of bits for message validity versus the data throughput of the system. The preamble portion of the message from the mobile phone to the base station contains four antenna selection fields. Note that the antenna selection bits occupy part of the message, which was conventionally used to recover symbol timing, so that symbol recovery by the base station is reduced if no other method is taken. . One such criterion can be used to increase the size of the preamble portion with respect to the data portion of the message, or to increase the overall length of the message. Both options result in a reduction in the data bandwidth of the system. According to one aspect of the present invention, no band reduction method is used, but a novel symbol timing recovery method is used. Referring to FIG. 8, symbol timing is derived from the output of the correlator through which the signal is applied. Generally, the received signal is sampled to provide a plurality of samples for each signal. In one embodiment of the invention, each symbol of the input signal is sampled ten times at the output of the correlator. The magnitude of the output of the correlator roughly corresponds to the magnitude of the center of the symbol received at that time. For each sample in the symbol, the sum of the samples is obtained, compared to the sum of all other samples, and compared to the largest sum that indicates the sample most likely to correspond to the center of the symbol. In other words, the receiver may calculate the following equation: Here, K is equal to the number of samples per symbol, and TOTAL is equal to the total number of samples per slot (all symbols). Note that this feature of the present invention uses all slots to determine symbol timing and uses that determination to extract each symbol. To achieve this feature of the present invention, the incoming message may be stored in dynamic memory while the symbol timing is being extracted. However, the symbol timing decision may start with the first reception of the message and does not have to wait for reception of all slots. Once the symbol timing is obtained, the receiver of the present invention uses a "moving window" correlator to find a single word. The present invention does not require the use of a threshold correlator. Thus, the correlator considers the finite portion of the incoming signal having the full slot length and determines where a single word is most likely. Once the correlator has determined the most probable location, the message in which the receiver's processor has received each bit of a single word expected to be examined a bit for bit in the reconstructed slot To determine if it exists. If a single word is found, the receiver assembles all framing around the single word since it has been determined where the single word appears in the frame. Once a single word has been successfully acquired, a single word in the subsequent frame is used to measure the drift between the transmitter and the receiver, and the receiver for that flow. May be used to adjust. By acquiring a single word in a subsequent frame, a small window around the time at which a single word is expected to appear is usually sufficient, reducing the processing burden on the receiver. There is no need to consider the frame. To assist the base stations in maintaining synchronization with each other so that they can accurately consider slot / frequency combinations, the system of the present invention may also include a common clock pulse that is periodically transmitted to all base stations. Good. The clock pulse may be generated from a relatively stable pulse source, such as from a typical switch used in connection with a base station. For example, in a Pulse Coded Modulation (PCM) system such as is commonly used in digital telephone applications, one of the PCM slots between the base station and the switch is received by all base stations, and the clock and It may be programmed periodically to carry a synchronization (or reset) pulse used to synchronize with the generated communication frame. Using a single stable clock assures data alignment and reduces hardware costs, since the base station does not need an expensive oscillator if the correct clock comes from the switch Help to do. Further, in the present invention, the mobile phone is relatively inexpensive by frequency correcting a reference clock (fixed to a precise clock such as a PCM clock from a switch) using an RF carrier received from a base station. A relatively inaccurate on-board reference clock may be used. In another aspect of the invention, a system includes a protocol that, upon user initiation, may require a bit error rate ("BER") test for communication between a remote unit and a base station. May be. The BER test may include transmissions from remote units, base stations, or both pseudo-random sequences. Both the base station and the remote (unit) may use the reception of such a sequence to determine the BER and (in the case of a base station) report the BER to the remote unit and display it to the user. . The displayed BER information is very useful for the system installer to determine and / or confirm the scope and performance of the system. This aspect of the invention is not limited to BER measurement, and the system of the invention may transmit signals or measure certain characteristics of the RF signal, such as signal strength. According to another feature of the invention, the message between the base station and the mobile phone may include a system identifier programmed into the mobile phone. The system identifier may be located in the message, for example, in the preamble part. The mobile phone and the base station then consider the system identifier and may completely ignore the message if it does not match the system identifier for the receiver. Thus, two completely separate systems may be present alongside each other in portions covering the same topographical area. Similarly, a mobile phone may be programmed to run on one or more installed systems, so that it is free to move from one system to another. By taking into account congestion and security, changing the system verification allowed for a particular mobile phone can provide a mobile phone with varying ability to access from various terrain areas. Similarly, the mobile phone of the present invention may be used in multiple wireless systems where the user does not need to initiate functions other than activating the remote unit (the administrator of each system providing access to the mobile phone). Must design the system to accept mobile phones). This feature is particularly useful in installations where different systems operate in different locations within the same (or adjacent) business premises. In such an installation, the user may move from one area of the location where a completely different wireless system is installed to another area, including the personal characteristics associated with the user. Maximum use. On the other hand, if two adjacent systems do not want to allow users of one system to use the other system, the only wireless system will automatically remove the unauthorized mobile phone. Ignore, and the mobile phone does not attempt to use the communication channel and base station used by the "foreign" system. The system of the present invention can also be used in conjunction with a radio pager (pager) and telephone system. At this point, the mobile phone may receive the alphanumeric message for display, and a ringer may be activated to alert the user of the message. When used as a pager, the mobile station cannot perform a telephone call to the user on the mobile phone, but simply uses the existing communication system to send the pager's messages. The remote units used in the combined pager / telephone wireless system are the same for all users, and some of the units used only for paging (paging selective radio) are low cost units without voice communication capability. You may. Referring again to FIG. 1, the system of the present invention is relatively easy to construct due to its structure. For example, the switch may be a digital switch with a BSIU 16 that can communicate with the base station 18 via the communication means 20. The communication means 20 may be as simple as two sets of twisted wires, of which two wires are used for data communication to the base station and two wires are used for data communication to the BSIU 16. Data communication on the four wires can be performed using a protocol known as E-1 to handle multiple digital messages that can occur simultaneously on each pair of wires. Further, since the four wires carry power and ground references to the base station, it is not necessary to integrate the base station into the building wires. In operation, the base station 18 can be mounted on a convenient surface, such as a wall or ceiling, and the four wires passed between the base station 18 and the BSIU 16. By using a common high-power programmable read-only memory ("PROM") coupled to the base station 18, a PROM can be used to apply output from the communication means 20 or available power lines. , Base station 18 is itself available. Once the base station 18 is utilized, a message may be sent to the BSIU requesting a download of the system single data and configuration. Since the base station 18 does not have an assigned frequency and performs a signal strength assessment first rather than the telephone location, a base station extension program is usually not required. The absence of this program makes installation of the system easier and provides for automatic restart of service after a power shortage or surge. In another aspect of the present invention shown in FIG. 10 (the same reference numerals are used for the same elements as in FIG. 1), the switch 10 used in the present invention is a digital switch as described above. It need not be a switch, but may be a conventional analog switch that interconnects the system with the public telephone network 12. In this system, a base station interface device (BSIA) 90 may be used as an interface between the digital wireless system and the conventional analog switch 10. BSIA brings all the functions of the BSUI described in FIG. 10 to the wireless system (base station 18 and mobile phone 22). In addition, the BSIA of the alternative system of FIG. 10 converts all digital communications to and from the cell phone into conventional analog communication and converts the conversion function request from cell phone 22 to a standard switch (eg, PBX) protocol. And convert to signaling. Alternatively, the BSIA 90 may be configured to perform the specific PBX-related functions in response to a specific user input by appropriately programming the mobile phone 22 (as described below), thereby providing a number of functions directly achieved by the mobile phone. That function may be executed. Still referring to FIG. 10, the BSIA may be located and controlled via a standard personal computer 91 or similar computer device that can be movably secured to the BSIA 90 if necessary. For example, a personal computer can be connected when a system administrator wants to perform a reconfiguration, start a test, or collect data on system performance. Software in personal computer 91 typically includes software for system deployment, upload, performance statistics and alarm analysis, and downloading new programs to BSIA and base stations. New or updated programming for the base station is easy and convenient by downloading such a program to the BSIA (or via the BSU in a system such as FIG. 1) for communication to the base station. Is achieved. Thus, the reprogramming of new and improved features does not require movement or access to the base station, which can significantly save manpower to maintain the installed system. BSIA (or BSUI) also has the ability for mobile phone users to execute macro commands with simple and short keystrokes. In macro performance, BSIA provides the necessary signals for the protocol to the switch, easily achieved with a single keystroke of a mobile phone. For example, if certain functions in the switch desired continuous communication of DTMF signals for numbers 1, 2, and 3, a single function key on a mobile phone would require that typical functions be required. To the BSIA. Also, the BSIA generates DTMF signals for numbers 1, 2, and 3 that are transmitted sequentially to the switch. The switch receives the DTMF signal, understands that the requested function is desired, and performs the operations conventionally required to perform the requested function. A set of macros may be programmed into the BSIA, some of which may be cell phone dependent, and thus generate different signals which are transmitted in the same key match on different phones. Furthermore, the set of macros may be changed for different types of switches to provide different switch protocols and the proper set downloaded to the BSIA during installation. According to another feature of the present invention, the mobile phone may include a display that can be programmed (via a base station) from a switch to accommodate features for the various phones in the system. After the system is installed and activated, a message may be sent from the switch to the phone to provide some features within the phone, and the message may control the display on the phone display. . For example, a telephone display could resemble a keypad and switch of a conventional landline telephone. By identifying the functions available to the telephone user, the switch may cause one telephone switch to perform a completely different function than the other telephone switch, and may provide a variety of functions programmed on the telephone display. It may be possible to display a simple image display. For example, in a phone display with five virtual switches, the top switch of one phone is used for the "hold" function and the (same switch) on another phone is "transfer" May be used for functions. Thus, the display of the first telephone is instructed to display "hold" in or near the image of the switch on the telephone display, while the second telephone "transfers" to the same location on the display. May be displayed. Modifications of the display and various features of the mobile phone used in the system can be easily realized by mainly using the switch and command structure of the present invention. In addition, when a mobile phone user is required to provide a user-related code, each phone can change the display and function in response to the user code, and the same phone can be used for user safety. Different levels and service levels will have different characteristics. The display unit displays the well-known alphanumeric messages and icons of existing cellular phones, such as "waiting for e-mall", battery level, speaker volume level, phone line status, etc. Or a graphical image suggesting or indicating an action may be used. One embodiment of the present invention may be arranged to take advantage of one or more of the following user interface characteristics that facilitate use of the remote unit. For example, one embodiment of the present invention involves a user dialing digits of a telephone number to be dialed, pressing an operating key (such as a "call" key), or first pressing an operating key. It may include a user protocol for dialing the telephone number digits to be dialed afterwards. The first method is similar to the user protocol common to existing cellular telephone systems, and the second method is similar to the protocol commonly used for existing cordless telephones. In the present invention, the user is given the option to use both protocols. In another convenient protocol that may be used with the present invention, the user presses the operating key twice to redial the last dialed telephone number. For example, the user may press the "call" key twice, in which case the first gets a dial tone and the second gets the last dialed number. The use of a single key assists the user by eliminating the need to search for keypads of different keys that display call and redial functions. In another convenient protocol, incoming telephone calls are reconnected on a special basis by the user of the remote unit. In this protocol, once a telephone call is received at the remote unit, the remote unit may display the telephone call in a standard manner, such as ringing or vibrating. Optionally, the remote unit may display the caller's telephone number or extension. The user may respond to the incoming telephone call in any manner, i.e. press the "ring" key to answer the call, press the "clear" key to silence the ringer and remain unanswered Or press the "End" key to automatically reconnect the call to another unit, such as another telephone, message recording system, or voice mail system. In still another aspect of the protocol that may be used with the present invention, the keyboard of the remote unit may be electronically locked so that only a limited number of keys are used. For example, the user may enter a predetermined key sequence to lock from all use of the phone (except for the unlock feature) or to lock the phone in a restricted state. In the restricted state, the user has three keys: an "unlock" key to restore all functions; a "power" key to turn off the remote unit; a "ring" key to answer incoming calls; May be used. By placing the remote unit in a restricted state, the remote unit is free to transport without having to worry about inadvertent or unauthorized key presses. While the embodiments of the present invention have been described above, the described embodiments are illustrative only, and will be understood by those skilled in the art to their equivalents, many variations, and the full range of modifications and alterations that will occur to those skilled in the art. As such, the scope of the invention is defined solely by the appended claims.

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), AL, AM, AT, A U, AZ, BA, BB, BG, BR, BY, CA, CH , CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE, HU, IL, IS, JP, KE, KG, K P, KR, KZ, LC, LK, LR, LS, LT, LU , LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, S I, SK, TJ, TM, TR, TT, UA, UG, US , UZ, VN (72) Inventor Schmel Bachinski             United States, Florida 32919             Luverne, West Nasa Boulevard             1025 (72) Inventor Daniel Tarhun             United States, Florida 32919             Luverne, West Nasa Boulevard             1025 (72) Inventor Keith Nuendolph             United States, Florida 32919             Luverne, West Nasa Boulevard             1025 (72) Inventor David Hockman             United States, Florida 32919             Luverne, West Nasa Boulevard             1025 (72) Inventor Perminder Second             United States, Florida 32919             Luverne, West Nasa Boulevard             1025 (72) Inventor Lami Hudder             United States, Florida 32919             Luverne, West Nasa Boulevard             1025 (72) Inventor Jay Klein             United States, Florida 32919             Luverne, West Nasa Boulevard             1025 (72) Inventor David Mesh             United States, Florida 32919             Luverne, West Nasa Boulevard             1025

Claims (1)

[Claims] 1. A telephone switch that interconnects the private telephone line with the public telephone network;   A plurality of base stations interconnecting a plurality of remote units to the private telephone line; Communication between a base station and said remote unit is achieved using RF communication;   The base station has a plurality of antennas, and   Each of the antennas at one of the base stations is physically located at the one base station. Characterized in that it may have directivity independent of other antennas of the station Communications system. 2. The base station is housed in a single housing. The communication system according to claim 1. 3. The base unit is fixed to a wall or ceiling and the antenna is 3. The communication system according to claim 2, wherein the communication system may be adjusted to obtain directivity. Stem. 4. Even if the antenna is mounted so as to rotate along the side of the housing, The communication system according to claim 2, wherein the communication system is good. 5. The antenna is suspended regardless of the slope of the surface to which the housing is fixed. Characterized in that it may have physical directivity to transmit a linearly polarized signal, The communication system according to claim 1. 6. The antenna is adapted for terrain changes and structures close to the base station. 6. The method according to claim 1, wherein the directivity may be physically adjusted. A communication system according to any one of the preceding claims. 7. A base station, an R for communicating from the base station to a remote telephone and a plurality of remote telephones; F means, each of said telephones having an alphanumeric display associated therewith; A telecommunications system comprising a switch for connecting said base station to a common telephone network; The stem,   Transmitting a programming message from the switch to the base station, A correlation programming message from a station to the remote telephone using the RF means. By sending it indicates that it has the property of being usable for programming. A telecommunications system characterized. 8. The programming message is displayed to the remote telephone user. The telecommunications system according to claim 7, characterized in that the external part changes its appearance. . 9. The correlation programming message is transmitted to the forward channel (fo) of the RF means. sent using the reserved operation code in the rward channel. 9. The telecommunications system according to claim 7, wherein: 10. With a list of available properties and a switch to implement said properties The base station maps the remote telephone key to the requested code. The telecommunications system according to any one of claims 7 to 9, characterized in that: 11. A switch, a plurality of base stations operatively connected to the switch, a plurality of remote A remote comprising a telephone and RF means for communicating between said base station and said telephone A communication system, wherein the improvement comprises a boot prom coupled to the base station.  prom), which allows the additional base station to communicate with the telecommunications system without substantial programming. Means to download configuration information from each of the switches that can be added to the system A telecommunications system characterized by: