MXPA96001268A - Systems and methods for access to the cellular deradiotelefono system without comparison deidentification of the system - Google Patents

Abstract

The present invention relates to a method for providing access to a cellular radiotelephone system by a cellular radiotelephone, the cellular radiotelephone system including a plurality of dedicated control channels and a plurality of combined access and paging channels associated with each other, each dedicated control channel and each combined paging and access channel transmitting a system identification unique to the cellular radiotelephone system, each access channel and combined paging channel also transmitting a digital color code, the access method comprising steps of: identifying at least one dedicated control channel having a predetermined system identification, prior to a required system access, identifying a plurality of first access and combined paging channels having the predetermined system identification, prior to a required system access, in response to an access of the required system, check whether at least one of the first combined access and paging channels can be used for system access, if at least one of the first combined access and paging channels can be used, use at least one of the first combined paging and access channels to provide access to the cellular radiotelephone system, without comparing the system identification transmitted by at least one of the first paging and access channels combined with a system identification that is stored in the cellular radiotelephone, if at least one of the first combined access and paging channels can not be used, identify a plurality of second access and paging channels combined, without comparing the system identification transmitted by the plurality of second access channels and paging combined with a system identification that is stored in the radiotelephone or cellular, comparing the digital color code of at least one of the plurality of second access and paging channels combined with the digital color code corresponding to at least one of the plurality of first access and paging channels combined, and if the digital color codes match, use at least one of the second plurality of combined access and paging channels to give access to the cellular radiotelephone system, without comparing the system identification transmitted by at least one of the second plurality of access and paging channels combined with a system identification that is stored in the cell phone radiotelephone

Description

"SYSTEMS AND METHODS FOR ACCESSING THE CELLULAR RADIOTELEPHONE SYSTEM WITHOUT COMPARISON OF IDENTIFICATION OF THE SYSTEM" FIELD OF THE INVENTION This invention relates to systems and methods of cellular radiotelephone and, more particularly, to systems and methods for access of the cellular radiotelephone to a cellular radiotelephone system.

BACKGROUND OF THE INVENTION Cellular radiotelephone systems are increasingly being used for wireless mobile communications. As is known to those skilled in the art, a cellular radiotelephone system is a wide area communications network that uses a frequency reuse pattern in a plurality of cells. The design and operation of an analog cellular phone system is described in an article called "Advanced Mobile Phone Service" by Blecher, IEEE Transactions on Vehicular Technology, Volume VT 29, Number 2, May 1980, Pages 238 to 244. It is made as well reference to the analog mobile cellular system as the "AMPS" system. Recently, digital cellular phone systems using a Time Division Multiple Access (TDMA) architecture have also been proposed and implemented. Standards have also been established through the Electronics Industries Association (EIA) and the Telecommunications Industries Association (TIA) for the American Digital Cellular Architecture (ADC), which is a dual-mode digital and analog system that follows the EIA / TIA IS-54B standard. Telephones implementing double mode architecture IS-54B are currently being sold by the concessionaire of the present invention. Different standards for digital cell phone systems have been enacted in Europe. The European digital cellular system referred to as GSM also uses a TDMA architecture. A cellular radiotelephone network includes a plurality of separate small radio zones called cells. Each cell includes a base station for transmitting and receiving messages to and from cellular radiotelephones that are placed within the cell scale. A plurality of base stations are connected to a Mobile Telephone Switching Office (MTSO) that acts as a controller for the system cell phone. The MTOS is also connected to the Public Switched Telephone Network (PSTN) to allow communications between cellular radiotelephones and telephones with wire lines. As used herein, the term "cellular radiotelephone" encompasses a wide variety of portable radiotelephone devices that have access to a cellular radiotelephone system. Cellular radiotelephones include hand-held portable telephones or bag phones and permanently mounted car cell phones. The term "cellular radiotelephone" also includes terminals that provide functions in addition to those of a cellular telephone, such as facsimile, data communications, data processing, word processing applications and other functions of personal communication systems. These high-function cellular radiotelephones are sometimes referred to as "Personal Communications Systems" (PCS). Each cell of a cellular radiotelephone system typically includes a plurality of double voice channels through which the messages of the cellular radiotelephone are carried. Each cell is also provided as a plurality of control channels to control the operation of cell phones and to assign voice channels. There are three basic types of control channels in the cellular redirect cell systems described by the IS-54B standard of EIA / TIA and other standards of the conventional cellular system. They are the dedicated control channels, the messenger call channels and the access channels. The cellular frequency band is typically divided into 832 channels of which 416 are assigned to a first carrier, known as "Carrier A", and 416 are assigned to a second carrier, known as "Carrier B". Each carrier has its own set of channels that are distinct and non-overlapping in a given geographical area. Therefore, it is ensured that during initial access, a cellular radiotelephone will give access to your home system (either Carrier A or Carrier B). Of the 416 channels assigned to each bearer, 21 channels are split to be used as Dedicated Control Channels. The Dedicated Control Channels are defined by the standard to occupy a specific limited channel scale in the cellular network. These Dedicated Control Channels are used by a cellular radiotelephone initially to find service in the system of a desired type, either A or B. Since the channel numbers and, therefore, the frequency of the dedicated control channels are know beforehand, the cellular radiotelephone can Explore these channels to determine if service is available. A plurality of Call Channels are also provided by Messenger. The Messenger Call Channels are channels to which cellular radiotelephones are tuned and await the messages of call by messenger or other control messages. A plurality of Access Channels are also provided. Access Channels are channels to which a cellular radiotelephone sends replies for call by messenger and other control messages or sends a request of origin in response to a request from the user to place a telephone call. A cellular bearer can define the Access Channels that are to be separated from the Call Channels by Messenger and place the Access Channels in any scale valid for the type of cellular system. Separate Messenger and Access Call Channels are typically not used, however, due to the complexity involved in establishing a cellular radiotelephone system in what is called a split call and access system. Accordingly, most systems combine the Call by Messenger and Access channels to provide what will be referred to herein as "Combined Channels".

Calling by Messenger and Access. "In systems using the Combined Calling Channels by Messenger and Access, a bit in the superior message data (CPA) informs the cellular radiotelephone that the call by messenger and access channels are the same. The cellular radiotelephone is energized, performs an initiation procedure with the cellular radiotelephone system.The cell phone usually first scans a stored scale or a set of Dedicated Control Channels that are assigned one per cell and used by the cellular radiotelephone system to transfer the digital control information between the MTSO and the cellular radiotelephone.There is transmitted a Multiple Bit System IDentification (SID) as part of the total digital information from the MTSO in the control channel. from this initial scan, the cellular radiotelephone selects the Dedicated Control Channel that has the highest signal strength and stores n the identification of the system of this control channel Dedicated in its memory. The channels of the Channel called by Messenger established are then scanned for the channels of greater intensity, and their identity is conserved or saved. When the Call by Messenger channels are scanned, the SID of the Call by Messenger channel and the Access Channel is compared to determine if an acceptable SID is present. It will be understood by those skilled in the art that an acceptable SID can be limited to the same SID as the Domestic SID or can broadly include a specific group of SIDs for which arrangements have been made by the household bearer or any other combination of criteria selected. After the initiation procedure described above is completed, the cellular radiotelephone accepts an "intermediate task" and waits for an indication that access to the system is required. An access to the system may be required in response to an indication by the MTSO that the cellular radiotelephone is being called, which will also be referred to as a "courier call". Other control messages that require a response from the cellular radiotelephone can also be received. Alternatively, the user of the cellular radiotelephone may try to place a telephone call and thus requires access to the cellular radiotelephone system. A major problem occurs when it comes to carrying out access to the system by means of a cellular radiotelephone, and the cellular radiotelephone is in a geographic area of overlap between the adjacent systems of the cellular radiotelephone. In this situation, the radiotelephone cellular can give access to the adjacent system when the cellular radiotelephone wishes only to give access to the "domestic" system. Since the adjacent system is not the one that gave rise to the telephone call to the cellular radiotelephone, and the cell phone has not registered to place phone calls in the adjacent cellular system, access to the system will fail. Alternatively, access to the system can occur through the adjacent system, thereby penalizing the cell phone with errant charges. Both of these situations are undesirable. A known solution which prevents undesired access to an adjacent system is described in US Pat. No. 4,905,301 to Krolopp et al., Entitled "Selective System Sean for Multizone Radiotelephone Subscriber Units". In accordance with the Krolopp et al patent, an attempt to give access to an unwanted radiotelephone system by comparing the SID transmitted in a Dedicated Control Channel of the desired radiotelephone system and the SID transmitted in an Access Channel during the process is avoided. of access. Access is allowed if the SID of the Dedicated Control Channel and the SIDs of the Access Channel coincide. The solution described above requires a comparison of the SIDs between the Dedicated Control Channel and the Access Channel before allowing access to the system. There is a need to provide methods and systems that allow the appropriate access of a cellular radiotelephone system by means of a cellular radiotelephone without requiring a comparison of the SID during access.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide improved cellular radiotelephone systems and methods. Another object of the invention is to provide improved systems and methods for accessing the cellular radiotelephone system. These and other objects are provided, in accordance with the present invention, by systems and methods for accessing the cellular radiotelephone system that does not require comparison of System IDentification (SID) during access. Two related aspects can be used to provide access to the cellular radiotelephone system without SID comparison. These two aspects can be used separately, preferably they are used in combination. The first aspect will be referred to as a method and system of "No Re-exploration" and the second aspect will be referred to as a method and system of "Comparison of DCC". A method and combination system uses the No Re-scan followed by the DCC Comparison if the No Re-scan can not be used. Both of these aspects allow access to the system compared to the SID. In accordance with the aspect of "No Re-exploration", during the initiation, and before accessing the required system, at least one Control Channel having the predetermined SID is identified. It will be understood by those skilled in the art that the predetermined SID may be one or more domestic SIDs that are permanently stored in the cellular radiotelephone by the carrier of the cellular radiotelephone during the initial activation of the cellular radiotelephone. However, due to agreements between cellular radiotelephone carriers, the predetermined SID may be a combination of the domestic SID and other SIDs for cellular carriers with whom wandering agreements are present. Also during the initiation and before accessing the required system, a plurality of Combined Call Channels are identified by Messenger and Access having the predetermined SID. Then, in response to an access to the required system, the cellular radiotelephone uses one of the Combined Call Channels by Messenger and Access or identified, and preferably the Combined Channel.

Called by Messenger and Access identified as having the highest signal strength during initiation, regardless of the SID transmitted through one of the Combined Call Channels by Messenger and Access identified. A re-exploration is not carried out. Instead, the Combined Call Channel by Messenger and Access that was identified during the initial scan is used to access the system. Not requiring a reexploration, the time to carry out 'an access to the system is reduced. In addition, since the initial scans are typically repeated every five minutes or less, the Non-Re-scan aspect will often result in satisfactory access without comparison of the SID. The "Compare DCC" aspect can be initiated if the Combined Call-by-Messenger and Access Channel obtained from the "No Re-scan" aspect has insufficient signal strength to provide access to the system. Alternatively, the aspect of Comparing the DCC can be initiated in a required system access without first performing the "No-Re-scan" aspect. In accordance with the aspect of "Compare the DCC" in response to a required access to the system, a re-exploration of the Access Channels is carried out and identifies a plurality of second Access Channels. The second Access Channels are identified independently of the SID transmitted through the second Access Channels. For example, the most intense Access Channels are identified in the re-exploration without comparing the SID of the second Access Channels with the SID of the dedicated control channel that was identified during the initiation. Instead, the Digital Color Code (DCC) of at least one of the second Access Channels is compared to the DCC of the corresponding Access channel that was identified during the initiation. As is well known to those skilled in the art, the DCC is a two-bit identifier which is conventionally used to generate a coded DCC to be used during access. If the DCCs match, the second identified Access Channel is used to give access to the cellular radiotelephone system, independently of the SID transmitted by the second Access Channel. It will be understood that an equalization of the DCC does not generate the access to a desired cellular radiotelephone system. In particular, since there are four values for the two-bit DCC, there is a maximum probability of 25 percent that the DCCs of the adjacent systems inadvertently coincide. However, cell phone carriers usually they ensure that the DCCs of the adjacent cells do not coincide, so the probability of access to the wrong system is actually much less than 25 percent. The present invention allows access to a system without the need for re-scanning. Since it may require up to 1.5 seconds to obtain an SID, the present invention provides quick access to the system in response to a user request or a system request. Furthermore, if a re-scan is required, it can be achieved without comparing the SIDs while still minimizing the possibility of accessing an unwanted cellular radio telephone system.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a functional diagram of two adjacent cellular and conventional overlapping radiotelephone systems. Figure 2 is an electrical functional diagram of a cellular radiotelephone. Figures 3A to 3C illustrate three alternative embodiments for providing access to a cellular radiotelephone system in accordance with the present invention.

Figures 4A to 4B illustrate detailed operations for initiating the cellular radiotelephone according to the present invention. Figures 5A to 5B illustrate the detailed operations for providing access to a cellular radiotelephone system in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES The present invention will now be described more fully below with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. The invention, however, may be encompassed in many different forms and should not be construed as limited to the embodiments set forth herein; instead, these embodiments are provided so that this disclosure will be complete and complete, and will transfer the scope of the invention to those skilled in the art. Equal numbers refer to the same elements. Referring now to Figure 1, a functional diagram of two conventional adjacent and overlapping cellular radiotelephone systems is illustrated. As shown, the first cellular radiotelephone system 101 includes a plurality of first cells 103a-103n, each of which is defined by a corresponding station of the first cellular base stations 104a-104n. Each first cellular base station 104a-104n is connected to a first mobile telephone switching office (MTSO) 105 to provide control and other well-known functions of the cellular radiotelephone system. The MTSO 105 also connects to the Public Switched Telephone Network (PSTN-the wire telephone network). A second cellular radiotelephone system 102 is also illustrated with the second cell 106a-106n, corresponding to the second stations 107a-107n of cellular bases and the second MTSO 108. The design of the cellular radiotelephone systems 101 and 102 is well known for those skilled in the art and will not be further described herein. For purposes of explanation, the operation of cellular systems conforming to EIA / TIA IS-54B Standard will now be described. However, it will be understood by those skilled in the art that the present invention can be used with any cellular system. A cellular cellular radiotelephone 110 is also shown in Figure 1. It will be understood that the cellular radiotelephone 110 can move freely across the geographical area and can typically obtain service either from the first cellular radio telephone system 101 or the second system 102 of cellular radiotelephone, depending on the arrangements made between the user of the cellular radiotelephone and each of the cellular systems. As shown in Figure 1, the cellular radiotelephone 110 has marched towards a geographic area in which the radio coverage of the cells 103c and the cells 106b overlap. It is desirable for the cellular telephone 110 to obtain service of the cellular radiotelephone system to which the cellular radiotelephone 110 has tuned its Dedicated Control Channel as for example, of the system 101. However, under the conditions shown in Figure 1, the cellular radiotelephone 110 may attempt to gain access to the system through the Messenger Call and Access Channels of the cellular radiotelephone system 102. The present invention helps to avoid this problem without requiring a comparison of the identification of the system in the process. Referring now to Figure 2, an electrical functional diagram of a cellular radiotelephone including an access means to the cellular radiotelephone system in accordance with the present invention will now be described. As shown, the cellular radiotelephone 110 includes a transceiver 201 or other means for communicating with the cellular radiotelephone system, the transceiver 201 is connected to the antenna 206. The cellular radiotelephone 110 further includes a control processor 204. A storage means 205 is electrically connected to the control processor 204 to provide a storage capacity for program and data information. The storage medium 205 may include a conventional read and write memory such as RAM or EEPROM as well as a read-only memory (ROM). The transceiver 201 may be selected to generate and receive signals conforming to any standard including but not limited to AMPS, ETACS, MT450, NMT900, GSM, DCS1800 or IS-54B. The transmitting circuit 202 and the receiving circuit 203 carry out the processing of transmitting and receiving signals, respectively. As further shown in Figure 2, the cellular radiotelephone 110 also typically includes a numeric keypad 207, a display device 208, a loudspeaker 209 and a microphone 211. In order to provide a computer communication terminal for receipt and transmission of audio, video and data signals and / or multiple media, the numeric keypad 207 may be a full-scale personal computer keyboard and a display device 208 may be a large display device. It can also be provided a browser 210 as well as other devices 212 such as disk drives and modems to provide a personal communication system (PCS) terminal. The design of the cellular radiotelephone 110 is well known to those skilled in the art and need not be further described herein. In accordance with the invention, the cellular radiotelephone 110 also includes a means for providing access to a cellular radiotelephone system. The means for accessing the cellular radiotelephone system is preferably encompassed in a program stored in the storage medium 205 which is carried out by the control processor 205 for controlling the components of the cellular radiotelephone 110 during an access to the system. However, it will also be understood by those skilled in the art that discrete hardware may also be provided for access control to the system. Referring now to Figures 3A to 3C, three alternative embodiments of the present invention are described. The embodiment of Figure 3A performs the "No Re-scanning" aspect of the present invention. The embodiment of Figure 3B performs the aspect of "Compare the DCC" and the embodiment of Figure 3C performs a combination of "No Re-scan" and "Compare the DCC". None of these modalities require a Comparison of the IDentification of the System (SID) as part of an access to the system. It will be understood by those skilled in the art that the operations described in Figures 3A to 3C are preferably carried out by the control processor 204 of Figure 2 under the control of the stored program. Referring again to Figures 3A, 3B and 3C, the operations begin by carrying out the initiation in Block 301. The initiation operations are defined for each standard of the cellular radiotelephone system. However, all initiation procedures have common elements. The present invention will be described with respect to the IS-54B standard. However, it will be understood by those skilled in the art that other standards of the cellular radiotelephone system may be used. Generally, during initiation, the Dedicated Control Channels are scanned to determine the most intense Dedicated Control Channels. The Dedicated Control Channels are then tuned in the order of higher signal strength to extract the higher information. If the SID of the Dedicated Control Channel is acceptable, then the Messenger Call Channel is scanned for the most intense Messenger Call Channels and the Call Channels by Most intense messenger are economized. These Messenger Call Channels are then tuned in the order of signal strength that decreases the higher information is extracted. Assuming that the SID matches that of the Dedicated Control Channel and assuming that the Messenger and Access Call Channels are not combined, the established Access Channel device is scanned and the more intense Access Channels are tuned to extract the information higher. Assuming the identification of the system matches then the most intense Access Channels are retained. Therefore, during the initiation, a set of more intense Dedicated Control Channels, Messenger Call Channels and Access Channels that belong to the home cellular radiotelephone system are established. After initiation, the system inputs the intermediate task in Block 302. The intermediate task is a state in which the cellular radiotelephone responds to the superior information, responds to the messages of call by messenger, responds to orders and responds to the initiation of the user of a call. The intermediate task is defined, for example, in Section 2.6.2 of IS-54B. Continuing with the description of Figures 3A to 3C, in Block 303 a test is made as to whether access to the system is required. Access to the system may be required as a result of a required response to a messenger call message or as a result of the user initiating a telephone call. When access to the system is required, the present invention will respond based on whether the No Re-scan, DCC Comparison or system access in combination is carried out. If the Reexploration is not carried out, then in Block 304 the more intense Messenger Call Channel that was obtained during the initiation and to which the cellular radiotelephone is currently tuned, is used to give access without carrying out a Subsequent SID comparison of the higher SID information that was received during system access. Accordingly, this operation uses the same Messenger Call Channel that was used during the initiation without performing a separate re-scan of the Call Channels by Messenger or Access. The access to the system then continues in Block 308. It will be understood that if the more intense Messenger Call Channel is of marginal intensity for continuous communications, the cellular radio telephone system can transmit a "Re-Assay Directed" message as part of the process of accessing the system in order to redirect the cellular radiotelephone to another channel game.

Referring to Figure 3B, in the DCC Compare operation, a re-exploration of the highest signal strength access channels previously preserved is carried out and the upper information is extracted in the more intense channel. The extracted upper information includes a Digital Color Code (DCC) value but does not include the SID. Then, in Block 306, the re-scanned Access Channel DCC is compared with the DCC of the Access Channel initially explored. If they match, access to the system in Block 30B is continued using the re-scanned Access Channel without the comparison of the SID. Figure 3C combines the operations of No Re-exploration and Comparison of DCC. Like Block 307, a test is conducted to determine if the Call Channel is usable by Messenger that was used during the initiation. For example, a test is made to determine the level of threshold received signal strength. If the Call Channel is usable by Messenger then the No Re-Scan operation takes place in Block 304. On the other hand, if the Call Channel by Messenger has received too low a signal strength, then it is carried A re-exploration is carried out in Block 305 and the DCC Comparison is carried out in Block 306.

Referring now to Figures 4A and 4B, the detailed operations to carry out the initiation will be described (Block 301 of Figures 3A-3C). It will be understood by those skilled in the art that all operations need not be carried out for specific embodiments of the invention and under specific rules of the cellular radiotelephone. Referring now to Figures 4A-4B, after energizing the cellular radiotelephone, the cellular radiotelephone must extract certain operating parameters from the permanent or semi-permanent memory 205. As shown in Block 401, one of the parameters is the identification of the domestic system (HSID). The cellular radiotelephone also initiates the data structures and different channel scales that are used to give access to the cellular radiotelephone system. A flag to indicate that the Access Channels have been scanned is cleared (set to FALSE). This flag is used when determining if the Messenger Call Channels need to be re-scanned after scanning the Access Channels and filling in the Access Table as described below. It will be understood by those skilled in the art that this operation only needs to be carried out when they are not using the Combined Call Channels by Messenger and Access. Referring now to Block 402 in order to obtain the service of the cellular radiotelephone system, the cellular radiotelephone must scan for Dedicated Control Channels that have been assigned to the type of system desired. It will be understood by those skilled in the art that the established Dedicated Control Channel is of the scale of channels specified by the Federal Communications Commission (FCC) in the United States and the cellular system specification for both cellular radiotelephone systems analog (IS-553) as double mode (IS-54B). The cellular radiotelephone scans the Dedicated Control Channels of the first Dedicated Control Channel to the last Dedicated Control Channel by measuring the Intensity Indication of the Received Signal (RSSI) of each of the channels. The cellular radiotelephone retains n of the most intense Dedicated Control Channels in the ordered frame called the Best Control List. Then, referring to Block 403, the cellular radiotelephone tunes to the most intense channel from the Best Control List and tries to synchronize and extract the superior information from the Dedicated Control Channel. If the superior information can not be found in the most intense channel, the cellular radiotelephone will will tune to the next channel in the list and try to get the superior information. After extracting the SID from the superior information, the cellular radiotelephone determines if the SID has an acceptable value in Block 404. This is usually carried out by purchasing the extracted SID against the HSID or the cooperation SID list. If the SID is not acceptable, then the cell phone will ignore the current Dedicated Control Channel, will tune to the next candidate channel in the Best Control List if one is available (Block 405), and again try to synchronize and extract the superior data of the channel in Block 403. If there are no candidate channels from the Best Control List, then the cellular radiotelephone may try to acquire the service in the alternative system or may modify what it considers to be an acceptable SID through an automatic action of the user in block 406. Operations for switching to an alternative system are known to those skilled in the art and need not be further described herein. Returning again to Block 404, once an acceptable SID has been found on one of the Dedicated Control Channels, the cellular radiotelephone will continue to process the upper message stream by extracting another information required to determine the Call Channel by System Messenger. The Messenger Call Channel is within a scale of channels that comprise the Call Channels by Messenger of the cellular radiotelephone system. This is limited between and includes channels of a first Channel of Call by Messenger to the last Channel of Call by Messenger. The cellular radiotelephone scans the Call Channel by Messenger in Block 408, and saves the m most intense channels in an ordered list called the Best Call List by Messenger. The Best Call List by Messenger is a list usually in descending order of RSSI, of the m most intense channels obtained from the scan of the Call Channel game by Messenger. Referring now to Block 409, the cellular radiotelephone tunes to a channel in the Best Call List by Messenger and tries to synchronize and extract the upper channel information. The cellular radiotelephone will extract the value of the SID from the superior information and compare that with the SID that was previously received in the Dedicated Control Channel in block 403. If the SID of the Call Channel by Messenger being examined does not match with the SID that was extracted from the Dedicated Control Channel (Block 410), then the others Channels from the Best Call List per Messenger are examined in Block 407. If there are no more channels in the Best Call List per Messenger to examine, then the Dedicated Control Channels are re-examined. A preferred system type change may also be carried out as already explained in Block 406. Returning again to Block 410, if the SID of a Call Channel per Messenger being examined does not match the SID that is being addressed. extracted in the Dedicated Control Channel, then the Access Scan Banner is examined to determine if the Access Channels have already been scanned in Block 411. If the Access Channels have already been scanned, then the top infomation is updated in Block 412 and entry to the intermediate task (Block 302, of Figures 3A-3C and 5). Referring again to Block 411, the Access Channels have not yet been scanned, then the access parameters of the upper message train that was received in the Call Channel by Messenger in Block 413 are extracted. If the system is using Combined Call Channels by Messenger and Access (Block 414), then the Current Messenger Call Channel is also an Access Channel. This channel number together with your RSSI and DCC are placed in an Access Box in Block 418. Because the system is using the Combined Messenger and Access Call Channels, the Access Channel device is the same as the Messenger Call Channel device. The Access Channel device does not have to be re-scanned and the Best Access List can be set equal to the Best Call List by Messenger in Block 419. The cellular radiotelephone then proceeds with tuning and examination of the SID of the Best List Access in Block 417 as will be described below. Returning to Block 414, if the system is not using the Combined Call Channels by Messenger and Access then the cellular radiotelephone retains the Call Channel by current Messenger and must determine the Access Channel apparatus based on the information extracted from the message train. Superiors in the Call Channel by Messenger in Block 415. It will be understood by those skilled in the art that the Access Channel apparatus is within a scale of channels comprising the Access Channels of the cellular system. The device is limited between and includes the channels of a first Access Channel to the last Access Channel. Referring to Block 416, the cellular radiotelephone then scans the Access Channel apparatus while retaining the strongest p-channels in the Best Access List in block 416. Referring now to Block 417, the cellular radiotelephone tunes to each channel in the Best Access List and tries to synchronize and extract the superior data. If the superior data is obtained, then the SID and the DCC of the upper message are extracted in block 317. The cellular radiotelephone will then compare the SID received in the Access Channel being examined to determine if it is acceptable, in block 420 If it is acceptable, the RSSI, the DCC and the channel number are stored in a Box of Access in block 421. A sample of the Access Table is shown below: ACCESS CHART Table Index RSSI DCC Channel Number 1 2 3 P-1 P Other formats of the Access Table will be understood by those skilled in the art. It is important to note that the Access Table contains the DCC in order to implement the DCC Comparison operation. It does not contain and does not need to contain the SID. The operations of tuning to a channel in the Access List, receiving a train of superior messages, extracting the SID and the DCC and optionally storing the values in the Access Table if it is acceptable (Blocks 417, 418 and 421), continues until that all channels of the Best Access List have been examined. See Block 422. Once the Best Access List has been used up, the Access Scanned Flag is graduated in Block 423. The CPA bit that was extracted from the Call Channel by messenger is then retested in Block 424 to determine if the system is using the Combined Call Channels by Messenger and Access in Block 424. If the answer is yes, then the cellular radiotelephone tunes to the first channel in the Access Table, acquires synchronization and updates the information of the superior message in Block 425. If the answer is no, the cellular radiotelephone returns to call the calling channel by Messenger previously preserved from the block 415, and tuned to it in Block 426. The cellular radiotelephone then gives input to the intermediate task that is also shown in the first block of Figure 5A. If the Combined Call by Messenger and Access Channels are not being used (Block 424), the cellular radiotelephone is diverted to Block 425 and enters the intermediate task. Referring now to Figures 5A and 5B, while in the intermediate task in Block 302, the cellular radiotelephone process system messages that are sent in the Call Channel by Messenger or Access, the cellular radiotelephone is monitoring in the present and responds to user actions in Block 501. (IS-54B section 2.6.2). If, due to a control message from the cellular radiotelephone system, the superior information of the system or the user's action the cellular radiotelephone must give access to the cellular radiotelephone system (Block 303), the cellular radiotelephone first graduates its parameters of intent to access in Block 506 as specified in the section of IS-54B number 2.6.3. 1 . These parameters include but are not limited to the maximum number of occupied faults and shocks and whether the cellular radiotelephone should wait for a control padding message before trying to obtain access.

First, in Block 307, a test is made of whether Call Channels by Messenger are usable. Therefore, as shown in Block 502, a test is made if the system is using the Combined Call Channels by Messenger and Access. If the answer is yes, a test is made in Block 503 if the Call Channel is usable by current Messenger. Examples of a test would be the R3SI level above a threshold value or the bit error rate less than a predetermined value. If the channel quality is acceptable in Block 503, then the cellular radiotelephone performs the "No Re-scan" operation using the Call Channel by Messenger for access without performing a comparison of the SID in Block 304 In particular, the access parameters are graduated in Block 504 and the access parameters of the system are recovered. The system access is continued in Block 505, for example, as specified in sections 2.6.3.3-2.6.3.14 of the IS-54B. It will be understood that the re-exploration of the Access Channels has been skipped (section 2.5.3.2 of IS-54B). Alternatively, if the cellular radiotelephone is operating in a cellular radiotelephone system without Combined Call Channels by Messenger and Access (Block 502) or the quality of the signal is not sufficient for use the Call Channel by current Messenger (Block 503), then the "Compare the DCC" operation is carried out. In Block 506, the access parameters are graduated and in block 507 a test is carried out as to whether the acceptable Access Channels previously have been stored in the Access Table. If the answer is yes, a re-exploration of the channels mentioned in the Access Table in Block 509 is carried out. If there are no channels in the Access Table, then the cellular radiotelephone carries out a re- normal system access scan as defined, for example, in section 2.6.3.2 of IS-54B, in Block 508. If there are entries in the Access Table, then a re-scan is performed in Block 305 of the Access Channels. In particular, in Block 509, the Access Channels that have been mentioned in the Access Table are re-scanned in Block 509. In Block 510, the cellular radiotelephone then tunes to the higher intensity channel from the Control Panel. Access and try to synchronize and obtain the superior data in Block 510. It will be understood that other criteria can be used to tune to a channel from the Access Table. For example, a larger change in the RSSI can be detected.

The cellular radiotelephone extracts the DCC value from the upper data and compares that to the DCC value that is previously stored for the Access Channel in the Access Table, in Block 306. If the DCC is the same, then the cellular radiotelephone will remove the 'system access parameters in Block 512 and then give input to the channel task of reverse control that it captures in Block 308. Alternatively, if the Access Channel DCC is not the same as that stored in the Access Table (Block 306), the cellular radiotelephone will select the next higher intensity channel in the Access Table and will attempt to obtain DCC synchronization and comparison until either an equalization is found or the Access Table is exhausted in Block 511. If the DCC match is not found, the cellular radiotelephone can enter the homework task. normal scan access channel (section 2.6.3.2 of the IS-54B) to find a channel and then give access to the system in Block 508. Modalida has been made available in the drawings and in the specification Typical preferred embodiments of the invention and even when specific terms are used, these are used in a generic and descriptive sense only and not for limitation purposes, the scope of the invention having been pointed out in the following claims.

Claims (40)

1. CLAIMS: 1. A method for providing access to a cellular radiotelephone system by means of a cellular radiotelephone, the cellular radio telephone system includes a plurality of Access Channels, the method for providing access comprises the steps of: initiating the cellular radiotelephone; wait for a required system access; and in response to the access of the required system, to give access to the cellular radiotelephone system using one of the plurality of Access Channels without taking into account the IDentification of the System of a channel of the plurality of Access Channels.
2. 2. A method of compliance with the Claim 1, wherein the cellular radiotelephone system includes a plurality of Dedicated Control Channels and a plurality of Combined Call Channels by Messenger and Access associated therewith, each Dedicated Control Channel and each Combined Call Channel by Messenger and Access transmits a System IDentification (SID) that is unique to the cellular radiotelephone system, each Combined Call Channel by Messenger and Access also transmits a Digital Color Code (DCC); wherein the initiation step comprises the steps of: identifying at least one Dedicated Control Channel having a predetermined System IDentification; and identifying a plurality of first Combined Messenger and Access System Channels having the identification of the predetermined system; and wherein the step of providing access comprises the steps of: in response to a required system access, testing whether at least one of the first Combined Call Channels by Messenger and Access is usable for access to the system; if at least one of the first channels Combined Call by Messenger and Access is usable, using at least one of the first Combined Call Channels by Messenger and Access to give access to the cellular radiotelephone system, regardless of the IDentification of the System transmitted by at least one of the first Channels Combined Call by Messenger and Access; if at least one of the first Combined Channels of Call by Messenger and Access is unusable, identify a plurality of seconds Combined Call Channels by Messenger and Access regardless of the IDentification of the System transmitted by the plurality of seconds Combined Call Channels by Messenger and Access; comparing the Digital Color Code of at least one channel of the plurality of second Combined Call Channels per Messenger and Access with the Digital Color Code of at least one corresponding channel of the plurality of first Combined Call Channels per Messenger and Access; and if the Digital Color Codes match, use at least one channel of the second plurality of Combined Call Channels per Messenger and Access to give access to the cellular radiotelephone system, regardless of the IDentification of the System transmitted by at least one channel of the second plurality of Combined Call Channels by Messenger and Access. A method according to Claim 2, wherein the step of identifying a plurality of first Combined Call Channels by Messenger and Access comprises the step of identifying a first Combined Call Channel by Messenger and Access having a signal strength received higher. 4. A method according to Claim 3, wherein the test step comprises the step of testing whether the received signal strength of the first Combined Call Channel by Messenger and Access exceeds a predetermined threshold. A method according to Claim 4, wherein the step of using at least one channel of the first Combined Call Channels by Messenger and Access comprises the step of using the first Combined Call Channel by Messenger and Access to give access to the cellular radiotelephone system. 6. A method according to Claim 2, wherein the step of identifying a plurality of First Combined Call Channels per Messenger and Access comprises the step of identifying a plurality of first Combined Call Channels per Messenger and Access having an intensity of the highest received signal and having the IDentification of the default System. 7. A method of compliance with the Claim 6, wherein the step of identifying a plurality of second Combined Call Channels per Messenger and Access comprises the step of identifying a plurality of second Combined Call Channels per Messenger and Access having a signal strength received higher regardless of the IDentification of the System. 8. A method according to Claim 7, wherein the step of comparing the Digital Color Code comprises the step of comparing the Digital Color Code of a channel of the plurality of second Combined Call Channels per Messenger and Access that have the highest received signal strength with the Digital Color Code of the corresponding channel of the plurality of first Combined Call Channels by Messenger and Access. 9. A method according to Claim 2, wherein the step of identifying a plurality of second Combined Call Channels per Messenger and Access comprises the step of storing at least some channels of the second plurality of Combined Call Channels per Messenger. and access in an Access Table, in an order of a received signal strength that decreases together with the corresponding Digital Color Code without identification of the corresponding system. 10. A method according to Claim 2, wherein the identification of the predetermined system comprises an IDentification of the Home System. 11. A method according to Claim 1, wherein the cellular radiotelephone system includes a plurality of Dedicated Control Channels and a plurality of Combined Call Channels by Messenger and Access associated therewith, each Dedicated Control Channel and the Combined Channel. Call by Messenger and Access transmit a System IDentification that is unique to the cellular radiotelephone system; wherein the initiation step comprises the steps of: identifying at least one Dedicated Control Channel having a predetermined System IDentification; and identifying a plurality of Combined Call Channels by Messenger and Access that have the IDentification of the predetermined System; and wherein the step of providing access comprises the step of: in response to an access to the required system using a channel of the Combined Call Channels by Messenger and Access identified to give access to the cellular radiotelephone system, regardless of the IDentification of the System transmitted by a channel of the Combined Call Channels by Messenger and Access identified. A method according to Claim 11, wherein the step of identifying a plurality of first Combined Call Channels by Messenger and Access comprises the step of identifying a first Combined Call Channel by Messenger and Access having a signal strength received higher. 13. A method of compliance with the Claim 12, wherein the test step comprises the step of testing whether the signal strength received from the first Combined Call Channel by Messenger and access exceeds a predetermined threshold. 14. A method of compliance with the Claim 13, wherein the step of using at least one of the first Combined Call Channels by Messenger and Access comprises the step of using the first Combined Call Channel by Messenger and Access to provide access to the cellular radiotelephone system. 15. A method according to Claim 1, wherein the cellular radiotelephone system includes a plurality of Dedicated Control Channels and a plurality of Access Channels associated therewith. Each Dedicated Control Channel and Channel Access transmits a System IDentification (SID) that is unique to the cellular radiotelephone system, and each Access Channel also transmits a Digital Color Code (DCC); wherein the initiation step comprises the steps of: identifying at least one Dedicated Control Channel that has a predetermined System IDentification; and identifying a plurality of the first Access Channels that have the IDentification of the predetermined System; and wherein the access step comprises the steps of: in response to an access to the required system, identifying a plurality of second Access Channels independently of the System IDentification transmitted by the plurality of seconds Access Channels; comparing the Digital Color Code of at least one channel of the plurality of second Access Channels with the Digital Color Code of at least one corresponding channel of the plurality of first Access Channels; Y if the Digital Color Codes match, use at least one channel of the second plurality of Access Channels to give access to the cellular radiotelephone system regardless of the IDentification of the System transmitted by at least one channel of the second plurality of Access Channels . 16. A method according to claim 15, wherein the step of identifying a plurality of first Combined Call Channels by Messenger and Access comprises the step of identifying a plurality of first Combined Call Channels by Messenger and Access having an intensity of the highest received signal and having the IDentification of the default System. A method according to claim 16, wherein the step of identifying a plurality of second Combined Call Channels per Messenger and Access comprises the step of identifying a plurality of second Combined Call Channels per Messenger and Access having an intensity of the highest received signal regardless of the IDentification of the System. 18. A method according to claim 17, wherein the step of comparing the Digital Color Code comprises the step of comparing the Code of Digital Color of a channel of the plurality of second Combined Channels Call by Messenger and Access having a higher received signal strength with the Digital Color Code of a corresponding channel of the plurality of first Combined Call Channels by Messenger and Access. 19. A method according to claim 18, wherein the step of identifying a plurality of second Combined Call Channels per Messenger and Access comprises the step of storing at least some channels of the second plurality of second Combined Call Channels per Messenger and Access in an Access Table, in order to decrease the intensity of the received signal together with the corresponding Digital Color Code and without the corresponding System Identification. 20. A method according to claim 15, wherein the IDentification of the predetermined System comprises a Domestic System Identification. 21. A cellular radiotelephone to provide access to a cellular radiotelephone system, the cellular radio telephone system includes a plurality of Access Channels, the cellular radiotelephone comprises: means for initiating the cellular radiotelephone; a means, which responds to the means of initiation, to wait for access to the required system; and a means that responds to an access to the system required to give access to the cellular radiotelephone system using a channel of the plurality of Access Channels without taking into account the IDentification of the System of one of the channels of the plurality of Access Channels. 22. A cellular radiotelephone according to claim 21, wherein the cellular radiotelephone system includes a plurality of Dedicated Control Channels and a plurality of Combined Call Channels by Messenger and Access associated therewith, each Dedicated Control Channel and each Combined Call Channel by Messenger and Access transmits a System Identification (SID) that is unique to the cellular radiotelephone system, each Combined Call Channel by Messenger and Access also transmits a Digital Color Code (DCC); wherein the initiating means comprises: a means, responsive to the activation of the cellular radiotelephone, to identify at least one Dedicated Control Channel having a predetermined System IDentification; and a means, which responds to the identification means of the Dedicated Control Channel to identify a plurality of first Combined Call Channels by - 46 - Messenger and Access that have the IDentification of the Default System; and wherein the means of access comprises: a means, which responds to an access to the system required to test whether at least one channel of the first Combined Channels of Call by Messenger and Access is usable for an access to the system; a means, which responds to the test medium, to use at the same time a channel of the first Combined Channels of Call by Messenger and Access to give access to the cellular radiotelephone system, independently of the IDentification of the System transmitted by at least one of the first Combined Call Channels by Messenger and Access if at least one of the first Combined Call Channels by Messenger and Access is usable; means, which responds to the test means, to identify a plurality of second Combined Call Channels per Messenger and Access regardless of the IDentification of the system transmitted by the plurality of second Combined Call Channels per Messenger and Access if at least it is unusable one of the first Combined Call Channels by Messenger and Access; a means, which responds to the means of identification of the second Combined Call Channels by Messenger and Access to compare the Digital Color code of at least one channel of the plurality of second Combined Call Channels per Messenger and Access with the Digital Color Code corresponding to at least one channel of the plurality of first Combined Channels of Call by Messenger and Access; and a means, which responds to the comparison means to use at least one channel of the second plurality of Combined Call Channels per Messenger and Access to give access to the cellular radio telephone system, regardless of the IDentification of the System transmitted by at least one channel of the second plurality of Combined Call Channels by Messenger and Access and the Digital Color Codes match. 23. A cellular radiotelephone according to claim 22, wherein the means for identifying a plurality of first Combined Call Channels by Messenger and Access comprises a means for identifying a first Combined Call Channel by Messenger and Access having an intensity of highest received signal. 24. A cellular radiotelephone according to claim 23, wherein the test means comprises means for testing whether the received signal strength of the first combined Calling Channel by Messenger and Access exceeds a predetermined threshold. 25. A cellular radiotelephone according to claim 24 wherein the means for using at least one channel of the first Combined Call Channels by Messenger and Access comprises a means for using the first Combined Channel by Messenger Call and Access to provide access to the same. cellular radiotelephone system. 26. A cellular radiotelephone according to claim 22 wherein the means for identifying a plurality of first Combined Call Channels per Messenger and Access comprises a means for identifying a plurality of first Combined Call Channels per Messenger and Access having a signal strength. received higher and having the IDentification of the default System. 27. A cellular radiotelephone in accordance with rei indication 26, wherein the means for identifying a plurality of second Combined Call Channels per Messenger and Access comprises a means for identifying a plurality of second Combined Call Channels per Messenger and Access that have a higher received signal strength regardless of the System IDentification. 28. A cellular radiotelephone according to claim 27, wherein the means for comparing the Digital Color Code comprises a means for comparing the Digital Color Code of a channel of the plurality of second Combined Call Channels per Messenger and Access having a higher received signal strength with the Digital Color Code of a corresponding channel of the plurality of first Combined Call Channels per Messenger and Access. 29. A cellular radiotelephone according to claim 22, wherein the means for identifying a plurality of second Combined Call Channels per Messenger and Access comprises a means for storing at least some of the second plurality of second Call Channels per Messenger and Access in an Access Table, and in an order where the intensity of the received signal decreases together with the corresponding Digital Color Code and without the corresponding System Identification. 30. A cellular radiotelephone according to claim 22 wherein the IDentification of the predetermined System comprises an IDentification of the Domestic System. 31. A cellular radiotelephone according to claim 21 wherein the cellular radiotelephone sisstema includes a plurality of Dedicated Control Channels and a plurality of Combined Call Channels by Messenger and Access associated therewith, each Channel of Dedicated Control and each Combined Call Channel by Messenger and Access transmits a System Identification that is unique to the Cellular Radio Telephone System; wherein the initiating means comprises: a means, responsive to the activation of the cellular radiotelephone, to identify at least one Dedicated Control Channel having a predetermined System IDentification; and a means, which responds to the means of identification of Dedicated Control Channel, to identify a plurality of Combined Call Channels by Messenger and Access that have the IDentification of the predetermined System; and wherein the means of access comprises: a means that responds to an access to the system required to use one of the Combined Call Channels by Messenger and Access identified to give access to the cellular radiotelephone system, independently of the IDentification of the System transmitted through one of the Combined Call Channels by Messenger and Access identified. 32. A cellular radiotelephone according to claim 31, wherein the meido to identify a plurality of first Combined Call Channels by Messenger and Access comprises a means to identify a first Combined Call Channel by Messenger and Access having a higher received signal strength. 33. A cellular radiotelephone according to Claim 32, wherein the test means comprises means for testing whether the received signal intensity of the first combined Calling Channel by Messenger and Access exceeds a predetermined threshold. 34. A cellular telephone radio according to Claim 33, wherein the means for using at least one channel of the first Combined Call Channels by Messenger and Access comprises a means for using the priMer Combined Call Channel by Messenger and Access to give access to the cellular radiotelephone system. 35. A cellular telephone radio according to Claim 21, wherein the cellular radiotelephone system includes a plurality of Dedicated Control Channels and a plurality of Access Channels associated therewith, each Dedicated Control Channel and each Access Channel transmits a System IDentification (SID) that is unique to the cellular radiotelephone system, each Access Channel also transmits a Digital Color Code (DCC); wherein the initiation means comprises: a means, which responds to the activation of the cellular radiotelephone to identify at least one Dedicated Control Channel that has a default System IDentification; and a means, which responds to the identification means of the Dedicated Control Channel to identify a plurality of first Access Channels having the IDentification of the predetermined System; and wherein the means of access comprises: a means, in response to an access to the system required to identify a plurality of second Access Channels independently of the IDentification of the System transmitted by the plurality of seconds Access Channels; means, which responds to the means of identification of the second Combined Channels of Call by Messenger and Access to compare the Digital Color Code of at least one channel of the plurality of seconds Access Channels with the Digital Color Code of minus one corresponding channel of the plurality of first Access Channels; and a means, which responds to the comparison means to use at least one channel of the second plurality of Access Channels to provide access to the cellular radiotelephone system, regardless of the IDentification of the System transmitted by at least one channel of the second plurality of Access Channels if the Digital Color Codes match. 36. A cellular radiotelephone according to Claim 35, wherein the means for identifying a plurality of first Combined Call Channels by Messenger and Access comprises a means for identifying a plurality of first Combined Call Channels by Messenger and Access having the same intensity of the highest received signal and having the IDentification of the default System. 37. A cellular radiotelephone according to Claim 36, wherein the means for identifying a plurality of second Combined Call Channels per Messenger and Access comprises a means for identifying a plurality of second Combined Call Channels per Messenger and Access having the same highest received signal strength, regardless of the IDentification of the System. 38. A cellular radiotelephone in accordance with Claim 37, wherein the means comparing the Digital Color Code comprises a means for comparing the Digital Color Code of a channel of the plurality of second Combined Call Channels per Messenger and Access having the highest received signal strength with the Digital Color Code of the channel corresponding to the plurality of first Combined Call Channels by Messenger and Access. 39. A cellular radiotelephone according to Claim 38, wherein the means for identifying a plurality of second Combined Call Channels per Messenger and Access comprises a means for storing at least some of the second plurality of second Combined Call Channels per Messenger and Access in an Access Table, in an order where the intensity of the received signal decreases together with the corresponding Digital Color Code and without the corresponding System IDentification. 40. A cellular radiotelephone according to Claim 35, wherein the IDentification of the predetermined System comprises an IDentification of the Home System. SYSTEMS AND METHODS FOR ACCESSING THE CELLULAR RADIOTELEPHONE SYSTEM WITHOUT COMPARISON OF IDENTIFICATION OF THE SYSTEM" SUMMARY OF THE INVENTION Access to a cellular radiotelephone system is provided by a cellular radiotelephone without requiring a comparison of the System Identification (SID) during access. The access is carried out eliminating a reexploration of the Access Channels during the access and using the Combined Call Channel by Messenger and Access that was identified during the initiation for access to the system. Alternatively, the Access Channels can be re-scanned during an access request and a comparison of the Digital Color Code with the channels initially scanned is carried out. If the Compared Digital Color Code matches, the identified channel is used to access the system regardless of its SID.