MXPA98002055A - System and method for assigning the dinam channel - Google Patents

Abstract

The present invention relates to a system and method for providing dynamic channel assignments in a microcellular system surrounded by a macrocellular system. The method characterizes the FR environment of the microcellular system and the macrocellular environment. They are then qualified in range channels according to the signal-to-interference ratio calculated from the measured RF characteristics. A call is assigned to the highest-ranked idle channel. All active calls are verified to ensure voice and call performance by forcing transfer to another channel before degradation occurs. In another modality, the system is autoconfigurable to changes in the macrocell configuration by including remote power adjustment and functionality for assigning Audio Tone Supervisor oar

Description

SYSTEM AND METHOD FOR ASSIGNMENT DB DYNAMIC CHANNEL FIELD OF THE INVENTION This invention relates to the field of wireless communication systems, and more particularly to the dynamic allocation of transmission channels in a cellular communications network. BACKGROUND OF THE INVENTION Switching systems for indoor wireless access allow wireless service providers, for example carriers of radio location services and cellular carriers, to provide wireless communications between a microcellular communication system and its surrounding macrocellular communications system. . In this structure, the microtec system generally contemplates an indoor communication system of construction, where the cells within the microcellular system refer to specific localized coverage areas within a macrocellular system.

Although considerable progress has been made with the use of wireless technology in microcell communications systems, for example in indoor systems, many technical problems remain. A problem area refers to the allocation of cellular communication channels between the indoor system and the surrounding macrocellular system. REF: 25649 Existing implementations of indoor channel allocation methods, focus narrowly on the ability to handle traffic, mobile speed and other similar factors. However, prior art systems do not address the aspects that are of primary interest to the users of the system, namely call processing and voice quality. A further disadvantage of these methods is that they require information regarding the macrocell configuration in order to allocate and distribute a channel to the system indoors. As a consequence, prior art systems must be updated each time a modification to the surrounding macroselular configuration is made. Another disadvantage of many prior art methods is that they require a predetermined or fixed radio frequency ("F") threshold to be set prior to initiating channel assignment. Other previously implemented methods have added the disadvantage of not having autonomous control over the methodology of channel allocation and, on the contrary, the methodology is initiated and controlled by a Mobile Services Switching Center ("MSC"). Accordingly, there is a need for a system and method that can dynamically allocate channels with respect to call performance and voice quality. COMPENDIUM OF THE INVENTION In accordance with the present invention, a system and method are provided that dynamically allocate channels of speech. transmission in a microtec communications system, with respect to the characteristics of a surrounding macroscelular communication system. The system of the present invention is an efficient method for dynamically choosing available cellular channels, based on call performance and voice quality. An exemplary embodiment of the system of the present invention utilizes a signal-to-interference matrix for every transmission channel to powerfully assign the highest performing idle channel to mobile users against call origin, call termination and requests. transfer. The high performance allocation in the system of the present invention is achieved by dynamically estimating and characterizing the surrounding RF environment within its own coverage area and the macrocell environment, to effect efficient sanal allocations for system users. A measured signal matrix is used for real-time signal-to-interference ratio triggering to determine channel assignments. As such, the system of the present invention does not require knowledge of the surrounding macrocellular configuration. Voice call and outgoing performance are also ensured by checking calls at rest and active in the system. Advantageously, the system of the present invention essentially assigns interference-free channels to both the origin calls and the calls in progress that have degraded in performance due to extra cellular activity. Additionally, the present invention advantageously utilizes remote Supervisory Audio Tone ("SAT" = Supervisory Audio Tone) energy allocation and remote power adjustment to further improve the quality of the dynamic channel allocation process. This added functionality allows the system of the present invention to be self-configuring since call performance can be maintained with current knowledge of the present or future macro-cellular configuration. A further advantage of the method of the present invention is that it operates within an existing call processing architecture. The implementation of the present invention is transparent to and does not require calls to the call processing functionality and as a consequence, the present invention can be implemented with a user activated on / off face characteristics. As such, the present invention is easily and immediately deployed in an existing wireless communication system.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present invention can be obtained from the consideration of the following description in conjunction with the drawings in which: FIGURE 1 illustrates a communications system having a macrocell communications system and a microselular communication system; FIGURE 2 is an illustrative flow chart for providing dynamic channel allocation according to the present invention; FIGURE 3 is an illustrative flow chart for providing RF characterization according to the present invention; FIGURE 4 is an illustrative flow chart for providing channel allocation according to the present invention; and FIGURE 5 is an illustrative flow chart for providing call verification in accordance with the present invention, DETAILED DESCRIPTION For clarity of explanation, the illustrative embodiment of the present invention comprising individual functional blocks (including functional blocks labeled as ") is presented. processors "). The functions that these blocks represent can be provided through the use of either physical or discrete hardware, including, but not limited to, physical equipment capable of running software. For example, the processor functions presented in Figures 2 - may provide a single discrete processor. (The use of the term "processor" or "controller" shall not be considered to refer exclusively to physical equipment capable of running software). Illustrative modalities may include hardware digital signal processor ("DSP") and / or icroprocessor, read-only memory ("ROM" = read-only-memory) to store software that performs the operations discussed below and random access memory ("RAM") to store results. Modalities of physical equipment with very large scale integration ("VLSI" "Very Large Scale Integration") as well as customized VLSI sirs in symbiosis with a DSP general purpose cirsuito, can also be provided. Although specific values are given for various parameters through the following description, it will be understood that these values are adjustable in such a way that the present invention can operate efficiently in any given environment and is used only here with predefined values. { for example see Appendix 1).

A system and method that allows dynamic channel assignments in a microcellular somunisation system with respect to the surrounding macrocellular communication system are provided. The present invention provides an efficient method for a misroselular communication system that dynamically chooses available high-performance cellular channels is its own coverage area to address both call origination, call termination and transfer. High performance assignation in the system of the present invention is achieved by dynamically estimating the surrounding RF environment within its own coverage area and the macrocell environment to make efficient channel allocations for the users of the system. Additionally, the present invention is self-configuring since call performance can be maintained without sonication of the surrounding macrocellular sonfiguration. In addition, the present invention is easily deployed in existing wireless communication networks as it operates within an existing call processing architecture. With reference to FIGURE 1, an exemplary system 100 is illustrated in which the methodology of the present invention can be advantageously employed. The system 100 illustrates a macroselular communication system 101, which includes a macrocell 110 in a communication link with a mobile user 120. A microcellular communication system 102 is illustrated as an indoor wireless access PBX system ("WAPBX" = indoor wireless acsess PBX) which includes a puffed 130 sensor to a first antenna 140 and a second antenna 150. The first antenna 140 is additionally in a communication link with a portable unit 160. Although an exemplary embodiment of the present invention relates to a indoor communications system, it will be understood that the present invention is applicable to any misrosellular comunisation system having a smaller service area within a surrounding macroselular communication system. In this sense, a microselular communication system is defined as having at least one selda. Now also with reference to FIGURE 2, a flow diagram 200 illustrating a method for dynamically allocating channels according to the present invention is illustrated. In general, the method of the present invention consists of a trifunctional stage, RF characterization 210, assignment of sanal 250 and call verifiability 260. In an exemplary embodiment of the present invention, RF sarastering is accomplished by making the controller 130 collect measurements of signal strength in both active and idle channels (block 220). For each channel at rest, the measurements are stored in a specific set of sanal so that a probability density function ("pdf" "prsbability density function") can be created for all channels. For astive channels, the measurements are stored in a set of service signals in such a way that a pdf can be created for the server. The server represents the logical front or logical cell of the WAPBX system 102. The interferers in each channel, for example, represent macrocells 110 or other WAPBX cells. The controller 130 will rotate periodically the pdf of servisio signal are the pdf of each channel to produce a pdf of signal-to-interferensia ("S /?") For each sanal (block 230). The pdf S / l will be integrated to obtain the cumulative distribution function ("cdf"). From the S / I cdf, the Ith percentile value will be extracted and all the channels will then rank in descending order by the value of the? Or * S / Ith percentile (block 240). It should be noted that in this mode, there is a limit to the number of measurements stored by sandal sada. When the limit is increased, the oldest measurements will be discarded in order to accept the most recent measurements. In daily operation, the pdfs will vary over time as extracellular activity increases or decreases in specific sectors of the surrounding macroselds. Not only will this approach follow the call patterns on a daily basis but it will allow the WAPBX 102 system to adapt to discontinuous RF engineering changes in the macrocell network.

The controller 130 will then assign the channels up to down from the list with S / I rank, such that the first assigned channel will have the best S / I ratio (block 250). Additional separation criteria between channels are not required since adjacent channel performance measurements are inherent in RF characterization. A final signal measurement will be done before the channel is allocated to ensure that the channel is free of interference. If not, then the next available channel in the S / I list in range is chosen and the assignment is repeated. In the exemplary embodiment of the present invention, call verification is performed so that active calls prevent call performance from degrading (block 260). In addition to verifying the signal strength, controller 130 will be able to verify the power of the call. Audio Tone Supervision ("SAT" »Supervisory Audio Tone) for each call. As will be understood, there are three available SATs, one of which is assigned to the system. As explained below, the SATs assist a cell that receives a call to identify or distinguish between an attention or service signal and an interference signal. The measurements will be made for all the SATs, so that an instantaneous S / I ratio can be determined for the active call. If the SAT S / l ratio falls below a threshold specified by the user, then the controller 130 will force a transfer to a new channel. As stated above, RF facestry is achieved by analyzing signal interference measurements of available sanalos. The service signal and the interference received by the WAPBX 160 laptop provide sufficient infrastructures to sarasterize the forward or downward link performance. These trajectories are illustrated in FIGURE 1 as the first portable 140-to-unit antenna 160 sends the service signal path 170 and the macro-110 first 140-to-portable antenna 160 sends the interference path 180. The performance of The ascending or inverse is illustrated in FIGURE 1 as the portable 160-to-first antenna 140 reverses the service signal path 171 and mobile 120-to-first antenna 140 inverts the interference path 181. In an exemplary embodiment, an The radio, for example a test radius or a voice radio, is used to measure signal strength and interference in active and quiescent channels. Now with reference to FIGURE 3, a flow chart 300 is illustrated which presents a method for characterizing the RF environment according to the present invention. It should be noted that block 302 represents a set of nuscle functions that are employed in the method of the present invention and for reasons of clarity, will be referred to by block 302 instead of separate functions after the initial explanation. The method of the present invention requires interfacing the RF environment before channel allocation decisions are effected. As a consequence, the sonometer 130 must collect measurements of signal strength in both active and quiescent channels. Upon initial system startup, or after any initialization of the entire system, all channels will be marked as idle (block 305). In an exemplary embodiment, the scanner 130 will scan through the entire list of sanalities, marking a signal strength measurement of 10 ms per channel (block 305.). Medidation can be achieved, for example by sonfiguring a radio that realizes Measurement in an external antenna Measurements are independent of SAT In this mode, the radio will scan through the channel list 100 times so that 100 measurements are made for each channel. dBm) will be stored per channel After the first 100 measurements reralized for all channels, the controller 130 will calculate an interference probability density function of 41 points in 2dB increments from -40 to -120 dBm (block 310). In an exemplary mode, a pdf is calculated by using a histogram that establishes a frequency account for each signal deposit, and then each account is normalized to the number of sample points. Since there is no service signal information available at startup (since calls have not yet been made), the 130strip will generate a pdf of service signal based on a normal log distribution using an average of -90 dBm and a deviation standard of 6 dB (see Appendix 2) (block 312). Similar to the pdf of interference for each channel, the pdf of the service signal will be given in stages of 2 dB and in the range of -40 to -120 dBm. In one embodiment, the controller 130 will then determine S / I by convolving each pdf of interference with the pdf of the service signal such that 05 cdf (k) *? pdf earvidor (n) pdf azßrz_ [k-n) n- = -8 The resulting 81-point signal-to-interferensia pdf is integrated to form a cumulative distribution function. Since the discrete pdf, this simply becomes a sum for each element cdf (i) * pdf (i) + cdf (i -l) where sdf (0) = pdf (0) (block 315). The control 130 will then determine for each distribution S / I, the value? Or * ala £ >; percentile when searching through the distribution to determine the two neighborhood points and perform a linear interpolation (block 320). The lowest percentile value will be the S / I ratio (in dB) in which 90 percent of the calls will experience this level of performance or better.The persistent S / I for all sanales are then assigned rank in descending order in such a way that the best performing sanales will be assigned first (block 322). Statistically, this will allow the controller 130 to allocate channels in a non-consuming way, ie allocate channels on an available basis as opposed to reserving a set of channels for purposes of this invention. As detailed below, the inactivity threshold now becomes an S / L threshold below which channels will not be assigned. In an alternate modality, the convolution of the pdfs can be achieved by considering that the interferensia distributions are approximately log-normal. Using this approach, the pdfs are integrated in sdfs and a least squares adjustment is made in each distribution to determine the slope and intercept. Under the consideration of log-nor al, the slope and intercept will produce the average and standard deviations. The convolusion then simply is a subtraction of the means and the square root of the sum of the standard deviations to the suadrado. fis / I 3 - yes 2 + CF; 2 In addition, considering the IO value, the "percentile" is 1,282 standard deviations separate from the resulting S / I average.

According to the present invention, the system uses signals of signal strength from "front" call processing (block 330) and "bottom" channel check at rest. { block 325). It should be noted that measurement information is not discarded by the controller 130 without being processed. This creates a statistically valid set of signal strength measurements that tracks configuration changes in the macrocell system over time. After initialization of the system, the controller 130 has characterized the RF environment and is ready to assign channels. When processing calls, the controller 130 will continue to make signal strength measurements both in the service channel and in the requested idle channels. However, as a background task to call processing, the controller 130 will scan through the entire channel list to continue measuring the signal strength in rest channels on a more uniform basis (block 327). This background measurement process does not differ from the initial interference measurement described previously. In an exemplary mode, a radio is configured to measure the signal by 10 ms on an antenna without consideration to SAT, a sanal is skipped if it is not at rest. As in the initial RF characterization, each measurement will be stored per channel.

When processing calls, the sonderer 130 will use the servo voice sanal to verify the intensity of sanal resibido of sada called sada 2 seconds (block 332). As detailed below, the measure must now be taken into account SAT, since SAT will be used to trigger the transferensias relasionadas to S / I. Similar to interferensla measurements, the service signal measurement will be stored, however the set of servers is channel independent. As the transfer requests are processed, the controller 130 will perform a final check before allocating a new channel to a call in progress (block 335). In one embodiment, a radio is configured to measure the signal strength received from the resting channel of the macro-cellular sirsunding system, to ensure that it is free from interference. A signal measurement of 10 ms without SAT, is performed using the radio in an antenna. As detailed below, if the final channel check indicates that the channel has been degraded since the last update, the method of the present invention will choose the next best channel at rest. This will be repeated until the call is assigned a channel. In accordance with the method of the present invention, the measurement of signal strength will be stored for each channel. Up to 1000 measurements of signal strength will be stored per channel and when this limit is reached, the oldest measurements will be eliminated (it is first to enter, the first to exit) to release the set by the most recent measurements (block 307), The controller 130 will update the S / I matrix by regenerating a new histogram through a channel when the number of new measurements taken from the last histogram was created exsede 250 (block 302), the controller 130 will determine the pdf of the interferensia and using the pdf of the existing servise signal, the convolved pdf S / I and the I0 * "tmo As the previously described percentile S / l percentile for the channel is then inserted into the previous range list of the l0ß "iBO * percentiles S / I and the old sanal value is removed. In exemplary mode, up to 1000 signal strength measurements will be stored for the server and when this limit is reached, the oldest measurements will be eliminated (ie first in, first out) to release the set by the most recent measurements . Again, controller 130 will regenerate a new histogram and pdf for the server when the number of new measurements taken since the last histogram was created exceeds 250. The first time the service signal pdf is updated, all values S / I will be resalled. It is necessary to remember that the pdf of the servisio signal was only estimated at the beginning due to the fact that calls were not active.

In an exemplary mode, a full scan of the entire channel list (395 voice channels) will take less than 10 seconds. The present invention will not prevent the operation of the controller 130 or a base station. Alternately, if unscrambling becomes a problem, as it could be in multiple-way, multiple-sectored WAPBX systems, a subset of channels can be created in such a way that the controller will scan the higher-performance channels more often to update The performance data. In this mode, the subset size for example can be determined from the current or projected use and an Erlang B calculation. If subsets are required, a subset-to-whole explorer analysis is suggested to ensure the freshness of the S matrix. / l. As will be understood, higher or lower subset-to-joint relationships can be employed. In a further embodiment, the present invention is applied to multiple sectors and multiple selves. Extensions of the method of the present invention to a multiple-spaced WAPBX cell (i.e., a cell having multiple sectors) require interfacing the signal intensity of interference and of service for each sector. In an exemplary multiple-sector mode, it is considered that the cells operate under the proviso that sanal is not assigned to two sestores simultaneously. Under these scenarios, it is not necessary to measure sector-to-sector interference. In other words, all interference is considered to come from the surrounding macrocellular system. In another modality, an exemplary multiple-sample WAPBX system allows the reuse of fresuensia, in which imply reuse or simultaneous operation of two voice sanales in the same fresuensia. Alternatively, a non-reusable WABPX system can be treated as a previous multisession script. It must be recognized that the RF sarasterization was previously defined on a channel-by-channel basis, except for the service signal, which is characterized by sector. For a multi-sealed WAPBX system with reuse, the macro-to-WAPBX interference must still be on a channel-by-sanal basis since the WAPBX controller does not have a massel cell kernel. However, within the WAPBX system, inter-WAPBX cell interference can be reduced to cell / sector pair combinations, signifying significantly the sanctity of data required by the system and method of the present invention. In this mode, all measurements of signal strength are grouped by sector, not by channel. In essence, the controller creates a signal matrix in which diagonally shifted elements represent the potential interference for a particular sestor pair and the diagonal elements represent the service signal. As the WAPBX system adds more cells, the sonometer simply expands the matrix. An S / I value will be determined (as previously disenribed) for the sada pair selda / sestor, such that the ssntrslador will not assign a sanal to two sestores simultaneously that have S / I ratios below some threshold specified by the user. It should be noted that this does not obviate the need for interfacing the macro-cellular system on a channel-by-channel basis but simplifies quantifying this inter-WAPBX interference. Now with reference to FIGURE 4, a flow chart 400 is illustrated which presents a method for allocating channels according to the present invention. Once the characterization of the RF environment is achieved, the controller 130 will then assign channels from the channel list of S / L range to the channel that has the best S / L ratio (block 405). As each new request for a channel is initiated, the controlr 130 will assign the best sanal at rest (block 410). The sontroladsr 130 always starts at the top of the list. As the calls are completed in the best performing sanal, these sanales again become available in such a way that new requests are initially assigned to a good channel (block 407). Controller 130 will not assign calls to channels with 104.ioo. S / I persents less than 17 dB. As will be learned, this ratio value ensures good performance 90% of the time.

No additional separation requirements are necessary since adjacent in-band components have already been taken into account for the RF characterization for each channel. Statistically, the channel will perform well regardless of the source of interference if its S / I ratio is high. In an exemplary embodiment, the sonder 130 will make a final signal strength measurement in the selected idle channel before allocating the channel to the call (block 415). This final verification provides added protection against an RF environment that has changed significantly since the last characterization. The signal to interference intensity should be less than the mobile interference floor, which is approximately -116.5 dBm, thus ensuring that the channel is free from interference. If not, then the next best available channel in the classified S / I list is chosen and verified. The allocation process is repeated until a channel is assigned to the call (block 420). In one modality, the final verification is performed using a radio set to measure the signal received by 10 ms on the external antenna without consideration of SAT, since the RF interface is based on the premise that all signal and interference measurements are used to update the S / I matrix, the value of the returned signal strength is added to the channel signal strength set. An advantage of the final interference check is that the controller 130 will add more sample points to channels csn higher proportions S / l, in effect to the busier channels. If a busy channel has been degraded because the macro-cellular configuration has gone off, the final interference check will continue to add new measurements to the sanal signal set even if the sanal will not be assigned, as a result, the sonometer 130 will more quickly astualize the list of sanales that if the sanal had been characterized initially as a deficient candidate. In a further embodiment, a service provider will have the option to deactivate the final interference check, thereby forcing the method of the present invention to rely solely on the S / 1 characterization. The compensation for the loss of performance security is the saving of the time resources of the controller 130, which may be convenient since the WAPBX system increases in size. Alternatively, it can be argued that deactivating this option will extract more processing time from the sensor 130 if more calls are configured in a degraded state and trigger transfer requests related to S / L. However, this signal degradation will not be too severe since the characterization will produce good statistical service.

Now with reference to FIGURE 5, a flow diagram 500 is illustrated which shows a method for verifying calls according to the present invention. Call verification is performed for active calls to ensure adequate performance. The controller 130 measures the SAT power level after the received signal has been modulated (block 505). Based on the SAT information, an S / l SAT value is calculated (block 510) and compared against a specific S / I SAT firing ratio per user (block 515). The predefined value for the firing ratio will be 17 dB.

If the S / l SAT value is below the threshold, then the controller 130 will force a transfer, thereby initiating the channel assignment process described above. (block 520). Frequent call verification will result in calls being transferred before the poor voice quality is noticeable to the subscriber. Under these conditions, the S / I rejection trigger will detect when a collision is about to take place. In this sense, the collision refers to the detection of interference in the channel that carries the service signal. In one embodiment, a circuit for detecting the SAT power level will be an auxiliary for the base station, which can send the SAT power level back to the sonometer 130.

The signal measurement to verify calls was previously described with reference to the face measurements. After the sonometer 130 has received the SAT power level, SAT POWER and the SAT fresuensia, the controller 130 then has sufficient information to output an instantaneous SAT S / T value. The indices of SAT modulation, ß, are known to be 1/3, the SAT radiant frequency,? SAt, is known to be 2trx5970 Hz, 2? Rx6030 Hz. If the interference effects are sufficiently small, the energy value average of the desired signal to the average energy of the interference signal is given by the following equation: S / I = 2 * SATPOWER ß3? 2-SATPOWER If the interference effects have to be taken into account, then a predetermined level (a displacement) constant) should be used in the above equation. For the SAT detector circuit to correctly filter SAT, the radiant frequency of the distortion components should be greater than 2trx90 Hz. In an exemplary embodiment of the system of the present invention, remote power adjustment and remote SAT allocation are required to support a self-configuring system. However, it will be noted that the system of the present invention will work without these features. In these modalities, it would be necessary to periodically revisit and re-engineer the WAPBX system to make changes not related to frequency in the surrounding macrocell network. Remote Power Adjustment ("RPA") is required if the control channel signals of the maslular system 10l are maintained at higher levels than the WAPBX control channel signals within the WAPBX 102 environment. If this occurs, then the WAPBX 102 system will not be able to process call requests because the macroselular cell exceeds the potency and will take the sontrol of the internal call.This is because the control channels used in an IS-20 interface protocol, For example, they are the same set for both the macroselular system and the myeloid system, and in modalities that use an IS-94 interface protocol, the additional spectrum allows the user microphones to explore the channels of control of the expanded Personal Communications Service. ("PCS" * Personal Communications Service.} Before exploring the existing cellular control channels In these systems, a different sontrol channel It is used for the microselular system. However, as stated above, micro-phones that are not IS-94 will require the RPA of the present invention.

In accordance with the present invention, RPA allows the controllary 130 to periodically check the signal intensity of the control channel of the bladder macroseldas and adjust the energy levels in compliance in order to ensure PM capture. In one embodiment, a radio measures the forward control channel signal on an external antenna. For this configuration, the antennas should be mounted on the perimeter of the sonoruss and the sanal energy of the sontrol should be adjusted to exceed the measured value, which is already a statistical average or the? OßsiBC > percentile This value can be moved by a constant representing the difference in propagation loss between the antenna and the location of the handset. The constant displacement that has a predefined value of 0 is obtained through field measurements when the system is installed. In general, the control channel energies in macroselular systems do not sap very often and a double somatosis per day is probably feasible. The second feature required for a self-configuring mode of the present invention is the remote SAT allocation. Similar to RPA, this feature is not necessary for the dynamic allocation of channels according to the present invention. As previously established, SATs assist cells in distinguishing between voice calls and interferers. In general, there are three situations that must be taken into account by the system. First, the system can support multiple calls in multiple sanales. Each call uses for example SAT i. This is a normal situation and does not represent a problem. Second, the system can receive a voice call with SAT l and an interfering ssn SAT 2. This represents moderate degradation that the cell can correct using the different SATs. The third situation is when the voice call and the interferer both use SAT l. This is referred to as co-channel. SAT co-interference, which represents a deterioration of the worst case, the co-SAT vesinos are not a problem with fixed frequency assignments, since the neighbors in general, are not also interferers. For the WAPBX system 102, however, the co-channel, under the so-SAT condition, was exasperated by the method of the present invention since it uses resting channels assigned to neighboring macrocells. In one embodiment, the method of the present invention overcomes this problem by choosing the SAT frequency less used by the neighborhood macrocells. Therefore, it is necessary to periodically verify SAT of the vesicle macroseldas. The selection criteria are based on relative SAT energy levels that are provided by the SAT detection circuit. When performing a scan through the controller of all sanal 130, the SAT will determine the statistically weakest of the three available and assign the SAT to be used by the WAPBX 102 system.

The SAT characterization is similar to the faceting of sanal exsepts because so many sample points are not required and the values do not need to be retained after configuration. Since there are not enough sample points for a valid io ** io ° persentil somparasión, an average value per SAT sada will suffice. The controller will use the SAT is the lowest average. In one embodiment, a radio can be configured to obtain desired information by measuring direct voice signal strength with SAT on an external antenna. Numerous modifications and alternate modalities of the invention will be apparent to those who are skilled in espesiality in view of the previous dessripsión. In accordance with this, this dissension must be considered as illustrative only and is for the purpose of illustrating those with skill in the technique in the best way to bring invention to taste. Details of the structure may be varied substantially without departing from the spirit of the invention and exclusive use of all modifications that fall within the scope of the appended claim is reserved. APPENDIX 1 Description Predefined Value Initial Number of Signal Measurements per Channel 100 Service Signal Average -90 APPENDIX 1 (Cont.) Description Default Value Standard Deviation of Service Signal 6 Front Measurement Interval 2 Total Number of Signal Measurements per Channel 1000 Number of Signal Measurements by Channel Update 250 Total Number of Signal Measurements by Server 1000 Number of Signal Measurements for Server Update 250 Size of Optional Channel Subclasses 64 Subset-to-Entire-Set Exploration Ratio 10 Cutoff Threshold for Channel Assignment I0 * si5lo% S / I 17 Interfering Signal Strength in Final Verification -116.5 SAT Trigger Threshold 17 Displacement with Loss of Propagation 0 APPENDIX 2 Generate Service Signal Distribution cdf and pdf service signal can be generated using a standardized normal distribution table N [0,1] that is defined in the range of values in the interval [-5,5] in step size of 0.01. For purposes of explanation, this table is stored in a set cdf and is constructed by the following formula: 2 for n and i e [-500,500], where both n and i are integers. An approximation for the error function can be found in most math books. The distribution of service signal of 41 -points Fs is defined in the range [m = -120, -40] dBm in stages 2 dB. For each, the index standard to the cdf table is calculated as follows: Here, μ is set to -90 and c is set to 6 dB. For each m, Fs is simply the cdf of the table search (norm). The resulting cdf differs to form pdf. The pdf is discrete, so that this simply becomes a subtraction for each element. pdf (i) = cdf (i) - cdf (i -l) It is noted that in relation to this date, the best method conosido by the solisitante to bring to the prststisa the sitada invention, is the one that is clear from this description of the invention. Having described the invention as above, the contents of the following are claimed as co or property:

Claims (28)

1. CLAIMS 1. A method to allocate channels to a misroselular communisation system surrounded by a massel cell system, the method is sarasterized because it stages the steps of: sarasterizing an RF environment of the misroselular system and the surrounding massesular environment; assign one of the sanales based on characteristics of the RF environment; and verify the channels to ensure call performance by allocating a better performance channel, if available from the channels based on astualized features of the RF environment. The method according to claim 1, characterized in that the characterizing step includes the steps of: generating a signal-to-interference ratio for each of the channels; and assigning a range to the channel by the signal-to-interference ratio in such a way that a channel with the highest available performance is assigned first. 3. The method according to claim 2, characterized in that the step of generating includes the steps of: calculating an interference probability density function from a set of interference signal measurements; calculate a probability density function of servise signal; and determining the signal-to-interference ratio from the probability function of the service signal and the interference probability density function. 4. The method of soundness with claim 3, characterized in that the probability function of the service signal is calculated using a normal log distribution with a determined average and a determined standard deviation. 5. The method according to claim 3, characterized in that the probability density function for service signal is calculated from a set of measurements. The method according to claim 1, characterized in that the step of determining includes the step of generating a signal-to-interference ratio for each of the channels; and the allocating stage includes the step of choosing the highest performance channel available from a classified set of signals-to-channel interference. 7. The sonification method is claim 6, characterized in that the assigning step further includes: performing a final signal strength measurement in a select channel before allocating the channel to a call; check if the measurement is below a certain threshold; and repeating the steps of making and verifying until the selected channel is above the determined threshold and the selected channel is assigned. 8. The method according to claim 1, characterized in that the step of verifying includes the steps of: calsulating a signal-to-interferensia rejection from a supervised audio tone energy for so-called astute; comparing the signal-to-interference ratio are a certain threshold; and request a transfer if the signal-to-interference ratio is below the determined threshold. 9. The method according to claim 8, which is sarasterized because it also includes the step of performing a final verification in a transfer requested per channel before completing the transfer. 10. The method according to claim 1, characterized in that it also includes the step of assigning a supervision audio tone based on a monitoring audio tone characterization of the macroselular system and the microselular system. 11. The method of soundness is claim 10, characterized in that the step of assigning a supervisory audio tone, includes the steps of: measuring supervisory audio tone energy levels employed by neighboring macrocells; determine a supervisory audio tone with the weakest energy level employed by neighboring macrocells; and naming the weakest monitoring audio tone to the microcellular system. 12. The method according to claim 10, characterized in that it also includes the step of adjusting control channel energy of the microselular system. 13. The method of soundness with claim 12, characterized in that the step of adjusting includes the steps of: measuring signal intensity of control channel of masroseldas vesinas in the masroselular system; The signal strength is a certain threshold; and instore the energy of the control sanales of the microcellular system if the signal intensity is above the threshold. 14. The method according to claim 1, characterized in that it also includes the step of adjusting control channel energy of the microcellular system. 15. The method according to claim 1, characterized in that the characterization step includes the step of generating a signal-to-interferensia recession for each of the channels, the method also includes the steps of: making measurements during the prosecution of call to update selected signal-to-interference ratios; explore all the channels in a certain interval of time to update the rejection of signal-to-interferensia of sanalos at rest; and astualize the rejection of signal-to-interference after a certain number of measurements have been received. 16. A system for dynamically assigning channels in a microselular system based on a macrosselular system, the seventh is called sarasterized because it includes: a radius to resolestar the signal measurements in one of the sanales; an operable controller for the sarasterization of an RF environment of the miscellar system and the macrocell system when using signal measurements; the sontrslador is also operable to assign one of the sanales are based on the characterization of RF environment to the microcellular system; and the controller is also operable to verify the channels to ensure call performance by allocating a better performance channel if available from the channels, based on up-to-date characteristics of the RF environment. 17. The compliance system csn claim 16, sarasterized because the driver includes: an adder to calculate a signal-to-interference rejection for each of the channels; and a trigger set to a certain threshold to determine a level of voice output of a call. 18. The sound system is the most important 16, sarasterized because the sonometer insulates: an integrator to record a signal-to-interference ratio for each of the sanales; and a slaster to rank a given set of channels by the signal-to-interference ratio, so that a better resting channel is assigned higher first. 19. The system according to claim 18, characterized in that the determined set includes the channels that have a signal-to-interference ratio over a certain threshold. 20. The system according to claim 18, characterized in that the radio outputs a final signal intensity measurement in a selected channel before assigning the selected channel to a call; the controller verifies that the final measurement is below a certain threshold; and the controller chooses a new channel if the selected channel is above the determined threshold, 21. The system according to claim 17, characterized in that the controller transfers a call to a new channel at rest if the trigger is activated. 22. The system according to claim 21, characterized in that the controller performs a final verification before completing a transfer to the new channel at rest. 23. The system according to claim 16, characterized in that the system also includes: a sirsuite detestor for an energy level of supervision audio tones in masroseldas vesinas; a comparator to determine a supervisory audio tone for weaker energy level; and means for naming or signaling the weakest monitoring audio tone to the microcellular system. 24. The compliance system is claim 23, characterized in that the controller verifies a control channel signal strength of neighboring macroscells; an analyzer to compare the intensity of the control channel signal against a determined energy threshold; and the sonucleor is operable to adjust an energy level in the microtec system, if the signal strength is above the determined energy threshold. 25. An apparatus for dynamically allocating channels in a microcellular system surrounded by a macrocellular system, the apparatus is characterized because it includes: a radio to collect signal measurements in each sanal; an operable sontrolator to characterize an RF environment of the microselular system and the massel cell system, when using signal measurements; the controller is also operable to assign one of the channels that are based on the characterization of the RF environment to the microcellular system; and the controller is also operable to verify the channels to ensure voice quality by assigning a better performance channel if it is available from the channels based on updated characteristics of the RF environment. 26. The apparatus of solidarity with the claim 25, sarasterizads because it also includes: a sirsuito detestor for an energy level of supervisory audio tones in neighboring cells; a comparator to determine a weaker energy level monitoring audio tone; and means for signaling the weakest monitoring audio tone to the microcellular system. 27. The compliance device is the claim 26, characterized in that the contrsladsr verifies a signal intensity of the sonucleus channel of neighboring macrocells; an analyzer for comparing the signal intensity of the sontrol channel is a determined energy threshold; and the controller is operable to adjust an energy level in the microcell system if the signal strength is above the determined energy threshold. 28. The apparatus according to claim 25, characterized in that the sonder establishes a control signal intensity for neighboring macrosels; An analyzer to monitor the signal strength for Sontrol Sanal is a determined energy threshold; and the sontroladsr is operable to adjust an energy level in the microselular system if the signal strength is above the determined energy threshold.