JP2002514869A - Method and apparatus for determining the digit length of a dialed number in a fixed wireless communication network - Google Patents

Abstract

Summary An improved call setup processing method in a fixed wireless network such as a wireless local loop (WLL) is disclosed. The method includes detecting that the caller goes off-hook on the telephone, in response to which a false dial tone is generated at the telephone handset. When the caller inputs a telephone number to the called party, for example, the first three digits are compared to a predetermined list of sequences stored in a look-up table. The number of digits in the telephone number is identified by matching a sequence with the relevant number of digits in the look-up table before finishing dialing. The call setup process is initiated by transmitting the entered digits to the processing exchange immediately after the last digit has been entered. In the first embodiment, if there is no matching numeric sequence, a “timeout” process is performed to determine when the last digit is input to start call setup. In the second embodiment, if there is no matching sequence, a connection is automatically established to the switch. The call setup process of the present invention allows for efficient use of the radio spectrum when a matching sequence is found, without the need to immediately connect to the switch during dialing. This potentially increases network capabilities. Furthermore, according to this method, the caller does not have to press the "call" button after dialing, and the calling sensation is more similar to a conventional wired service.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

In general, the invention relates to wireless-based wireless communication networks, such as wireless local loops. Further, the present invention particularly relates to a technique for determining a digit length to automatically start call setup before finishing dialing.

[0002]

[Prior art]

An evolving form of wireless communication network is the fixed wireless network, more commonly known as wireless local loop (WLL). W
An important reason for the increasing adoption of LLs is the relative simplicity and cost advantages of installing them on traditional wired networks. The relatively high cost of installing a wired network, also called the public switched telephone network (PSTN), generally relates to the installation of transmission lines and associated equipment. This is especially true in the countryside and other sparsely populated areas. This is because the cost of installing relatively few wires over very long distances can be very high. Therefore, when considering the cost of setting up a new communication network, many operators opt for a fixed radio based solution such as WLL. WLL, when connected to the PSTN, provides users with quality access to telecommunications services.

[0003] WLLs are generally accepted in many areas of major interest in setup and installation costs, as using wireless services instead of wired services can save considerable infrastructure costs. It is. The same is true in areas where it is desirable to deploy existing telecommunications processing capabilities at high speed and at low cost.
Other possible applications may include use in environments where local or internal communication is required. Such internal communication may take place via a private branch exchange (PBX) that calls the correct party in a local environment. Communication with external elements can be achieved by linking the PBX to the PSTN.
For example, this type of telecommunications infrastructure may be desirable at remote sites that are configured for short-term (as well as long-term) use, such as, for example, laboratories that are far from oil-producing sites.

[0004] WLL networks and standard wireless mobile communications networks often function similarly. For example, a wireless propagation path is used as a communication link between a transceiver unit and a serving base station (BS) and operates instead of a wire. The telephone is connected to a transceiver unit that performs wireless communication with the BS. As a result, many WLLs have adopted digital advanced mobile phone systems (D-AMP) in addition to standards based on code division multiple access (CDMA) technology.
S) and time division multiple access (such as Global System for Mobile Communications (GSM)).
It operates according to existing standards based on TDMA) technology. Thus, both of these standards have relatively low installation costs, many advantages such as disconnected access to telecommunication services, and disadvantages such as relatively long call setup times that are typically inherent in current wireless-based communications. To share a lot of.

As those skilled in the art are aware, the techniques for making calls to wireless-based networks are quite different from making calls in traditional PSTN networks.
In particular, the WLL call setup process is quite different from the conventional PSTN call setup process, and therefore the calling sensation of the user is quite different. One major difference regarding WLL call setup is that there is a significant delay between when the user dials the number and when the connection is finally made. This delay is typical in wireless based communication systems such as cellular networks. Since the link with the exchange (or switch) is not usually established immediately after the user dials, the radio spectrum is tied up during dialing.

In a typical call setup process in a wireless-based network, a caller enters a sequence representing the telephone number of a desired party. This is stored in the telephone as digital data. When the caller presses the 'send' key, the digits are then transmitted to the processing exchange. This allows efficient use of the inadequate resources of the radio spectrum. Once the appropriate checks have been completed, and if it is determined that a connection can be made, a voice channel is allocated for the outgoing call.
This process can take several seconds, with a delay that is perceptible to the caller. This is in contrast to the traditional call setup process of a conventional wired system where a direct connection to the switch is made as soon as the telephone goes off-hook.

[0007] Efforts have been made to improve the call setup process. One approach involves monitoring the elapsed time between the dialed numbers so as to determine when the user enters the last number. According to this, the number is transmitted to the switch which performs the processing automatically. This method is called a "time-out" method and operates by concluding that dialing is over when a preset time has elapsed. However, this technique has the disadvantage that its elapsed time imposes an additional delay during call setup. Further discussion of other techniques for dealing with call setup can be found in PCT International Publication No. WO 96/32824
"Wireless Units and Methods for Connecting Fixed User Stations to WLL Systems" (published October 17, 1996).

[0008]

[Problems to be solved by the invention]

In view of the above, an object of the present invention is to solve the problem that an immediate connection to the exchange is not established during dialing, and to provide a method for eliminating the caller's operation of pressing 'call' after dialing. Is to do. According to this, the radio spectrum can be more effectively used during the call setting process, and the bandwidth can be saved. The other purpose is
Reduces delays in call setup processing compared to conventional methods that perform "timeout" processing to determine the number of dialed digits, and is less uncomfortable in fixed wireless environments compared to traditional wired communication To provide a calling sensation.

[0009]

[Means for Solving the Problems]

Briefly, in accordance with the following embodiments, the present invention automatically initiates the call setup process, before dialing out by the caller and before connecting to the switch, A method for determining the number of digits is disclosed. The method disclosed herein includes detecting when a caller performs a standard telephone off-hook, for example, by raising the receiver. In response to the off-hook state, the pseudo dial tone
Generated by a transceiver station associated with the handset, the dial tone is audibly perceived by the user. The caller then enters a series of numbers representing the desired telephone number. For example, the sequence of the first three numbers entered is compared to a predetermined list stored in a look-up table in the memory of the transceiver station connected to the telephone. The number of digits in a telephone number is also identified by searching the number of digits for a matching sequence of numbers stored in memory before finishing dialing by the caller. The call setup process is started by sending the entered digits to the processing exchange immediately after the last number has been entered. In the case of a sequence that cannot be determined in the comparison step, in the first embodiment, a “time-out” process is performed, and it is determined when the last number is input in order to start call setting. In the second embodiment, the connection to the switch is established in a process similar to conventional wired technology to complete the call.

The present invention provides a technique for improving a call setup process in a fixed wireless environment, for example, a wireless local loop, and the calling experience can be compared with a conventional case of making a wired call. In addition, bandwidth is not used while dialing. Therefore, it is possible to use the radio spectrum more efficiently. In another aspect, the present invention also eliminates the need for the caller to press 'Call' after entering a telephone number, and in some cases, if a matched sequence is found, is associated with a "timeout" process Eliminate delays. These and other advantages of the present invention include:
It will become apparent from a reading of the following detailed description, and upon reference to the various drawings.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a typical simplified radio-based wireless local loop (WLL)
Shown about network. WLL includes telephone 100. This phone 1
00 operates with standard dual tone multiple frequency (DTMF) dial tones and is coupled to transceiver station 102. Typically, telephone 100 is a standard telephone used to improve the cost effectiveness of the network for traditional wired telephone services. When the user goes off-hook, a simulated dial tone is generated at the receiving telephone 100 by the transceiver station 102. The simulated dial tone is presented to the caller as a communication aid, and the telephone 100 more closely resembles the operation of a traditional wired telephone. Transceiver station 102 contains all the necessary logic to enable two-way wireless communication over air interface 103 at the closest base station (BS) 104. And the mobile switching center (
MSC) 106 is connected to BS 104 by digital communication link 108. It should be noted that a typical WLL network includes multiple BSs, and that only a single BS is shown here for clarity. In addition, a plurality of telephones
02, which is also not shown for similar reasons.

A WLL network may operate according to established standards, such as, for example, the Digital Advanced Mobile Phone System (D-AMPS). To complete a call to an external telephone 112, the MSC 106 is connected to a public switched telephone network 114 as shown. For connection in a local environment such as a company, a private branch exchange (PBX) may be used instead of the MSC. The operation of the wireless communication on the air interface 103 includes transmission of at least one control channel and many voice channels. The control channel includes commands and control signals necessary for communication between the BS and the transceiver station 102, and the voice channel mainly includes data related to voice communication. In the air interface, the voice and control channels can operate in digital mode, analog mode, or both, according to established network protocols. Also, when operating in digital mode, data related to the conversation is transmitted in a particular time slot in a radio frequency carrier, while in analog mode the data is transmitted in a dedicated frequency carrier.

In accordance with an exemplary concept of the invention, a method for improving a call setup procedure in a WLL network will now be described. The method includes a technique for determining the length of a dialed number by recognizing an initial sequence of numbers entered before being fully dialed. During dialing, this opens up some of the radio spectrum, since the connection to the switch is not established, and thus can increase the processing power of the network. Further, eliminating the step of requiring the caller to press the 'send' key upon completion of dialing may have the effect of reducing the delay that may occur during the call setup process.

Referring now to FIG. 2 a, there is shown a flow chart illustrating a method for operating a call setup of an exemplary first embodiment that operates in accordance with the present invention. Step 200
The telephone (100 in FIG. 1) goes off-hook by the caller wishing to initiate a call. This off-hook condition is detected by the transceiver station 102. Then, at step 202, a simulated dial tone is generated at this transceiver station 102 and transmitted to the handset of the telephone to confirm that everything is functioning properly and the telephone is ready to accept dialing. Notify the user. In step 204, the caller enters the called party number. This number is stored in the memory of transceiver station 102 for later transmission to the processing switch. When the caller enters a numbered sequence, step 206 compares the sequence to its corresponding digit length contained in a look-up table in the transceiver station memory. If the sequence is known, that is, if a matching sequence is found in memory, the transceiver station awaits at step 208 the receipt of the correct number of digits specified in the look-up table. After entering the correct number of digits, the transceiver station releases the line to the switch and automatically initiates the 'originating' procedure to send the digits for processing and complete the call (step 212). If the sequence is not known (step 210), ie, if the sequence is not found in memory, then a "timeout" operation is performed to determine when dialing has ended. The "timeout" operation assumes that the last digit has been entered after a preset period of time, without a digit being entered. As an example, a time limit of approximately 5 seconds could be used. If the phone does not receive the input within the elapsed time, an 'outgoing' is generated.

FIG. 2 b shows a call setup procedure that operates according to a second embodiment of the present invention. The call setting processing step of the second embodiment is different from that of the first embodiment in comparison step 2
It is substantially the same up to the point of 06. As described above, if it finds a matched sequence, transceiver station 102 waits to receive the correct number of digits found in the memory look-up table before initiating the call setup shown in step 212 (step 208). If the sequence is not found, a connection to the switch is established at step 214. This terminates the call in a conventional manner as in a conventional wired system (step 216). Once the connection has been set up, transceiver station 102 will continue to send the digits received and send the numbers entered and received by the user. In this way, the delay time is reduced as compared to using a “timeout” technique, but at the expense of utilizing bandwidth that may potentially reduce the processing power of the network. For some applications, this trade-off is acceptable or even desirable in markets where processing power is not a major issue.

FIG. 3 shows an exemplary look-up table that can be used in accordance with the present invention at step 206. The look-up table includes a series of predetermined sequences, which are stored with the corresponding number of digits. According to a preferred embodiment, a series of 3
One number is usually sufficient to confirm the proper length of the number to be called. It should be noted that more complex numbering schemes may require longer sequences to confirm their length. Different numbering schemes may be implemented in different regions. As an example, telephone numbers with different numbers of digits may be assigned for each region. In general, a specified length is associated with a designated three-digit local number or a sequence of numbers. For example, in Sweden, generally, rural areas are assigned a 6-digit telephone number and urban areas with a 7-digit telephone number. Such a six digit telephone number is known, as indicated by reference numeral 302, and is easily identified by its first three digits. Similarly, a seven-digit telephone number can be identified through their local code (304). Information about the area code is readily available through local telephone companies or telecom providers. Such information is then used to update table entries when the numbering system changes. In addition, the method is usefully applicable in rural areas that use a standardized telephone numbering system, such as the United States, where almost all numbers are standard seven digits. By listing in a table, for example, 911 emergency telephone numbers and operator assistance calls, by assuming that all telephone numbers except for a few special sequences are seven digits,
Applicable.

When dialing a long distance or international call, it is usually necessary to dial a special number first. That is, it is entered to indicate a long distance call to the telephone company's switch. Generally, in the United States, callers need to complete a call,
Required to dial a zero (or one for direct dialing) and a three-digit area code before the seven-digit telephone number. Similarly, an international call is preceded by the area code, the area code, and the number 011 (00 in Sweden).
9). In a local environment, such as operation within a PBX, the extension or extension number is typically four or five digits. To extend this environment, a look-up table can be constructed to assume a standard number of digits. To dial outside of the PBX environment, access to an outside line is usually
Dial 9 or another specific number before the phone number. The look-up table can also be configured to confirm that an outside line has been requested. That is, by analyzing the first number (308), the number of digits of the subsequent number can be determined.

According to this embodiment, this table is stored in the memory of the transceiver station and can be updated by adding / deleting or changing entries. Digital Advanced Mobile Phone System (D-AMPS) IS-136
, For example, the data in the telephones is updated via wireless means, thus eliminating the need to manually update each telephone. Such capabilities are included in over-the-teleservice (OATS) functions, such as Short Message Service (SMS). Using the known SMS function as a multipoint broadcast technique, the transceiver station (102) can be used to update the look-up table (FIG. 3).
) Can be configured. In providing such a function, an SMS message can be marked to indicate that a particular message contains information about a lookup table, as known by those skilled in the art. Enables convenient large-scale updates without having to program individual stations. It should be noted that similar broadcast techniques are used in other standards, such as GSM, and can be used in a similar manner.

The present invention relates to a method for determining the number of digits of a number to be dialed by a user before finishing dialing. As a result, the system can automatically start the call setting process, and does not receive any further intervention from the user once the last digit has been entered. In the above embodiment, no connection to the switch is required, and therefore no use of the radio spectrum during dialing is required. Further, in situations where a connection to a switch is made, the delay associated with call setup as perceived in most wireless-based telecommunications is often reduced, resulting in a less uncomfortable calling sensation compared to traditional wired services. Can be obtained.

Here, only typical embodiments are shown, and those skilled in the art may change the processing steps without departing from the spirit and scope of the present invention. And that changes can be made. The invention is particularly suitable for mobile telecommunications systems such as cellular systems in addition to fixed wireless systems. Further, the present invention may use mobile terminals instead of telephones and transceiver stations described as fixed wireless applications. Further, the present invention is applicable to a multi-line terminal such as a PBX environment as well as a single-line terminal environment. All such changes and modifications are intended to be included within the scope of the present invention as defined by the appended claims.

[Brief description of the drawings]

FIG. 1 illustrates an exemplary simplified wireless local loop (WLL) network.

FIG. 2A is a flowchart illustrating a call setting process according to the first embodiment of the present invention.

FIG. 2B is a flowchart illustrating a call setting process according to the second embodiment of the present invention.

FIG. 3 is a diagram showing an example of a lookup table that can be used in the embodiment.

[Procedural Amendment] Submission of translation of Article 34 Amendment of the Patent Cooperation Treaty

[Submission date] May 19, 2000 (2000.5.19)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR , BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS , JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZA, ZW [Continued from summary] Effective use of geospectrum And This potentially increases network capacity. In addition, this method eliminates the need for the caller to press the "call" button after dialing, and the call feel is more similar to traditional wireline services.

Claims (15)

[Claims] 1. A method for initiating a call setup process in a fixed wireless network including a switching center, a base station, a transceiver station, and at least one telephone, the method comprising:
Detecting a condition when the caller goes off-hook on the telephone; generating a simulated dial tone that can be heard on the handset of the telephone in response to the detected off-hook; Receiving from the telephone a set of numbers representing the called party's telephone number; comparing the input set of numbers with a sequence list pre-stored in a look-up table and associated digits. A comparing step; a step of determining a digit length of a number to be inputted before dialing is completed based on the number of digits of the sequence determined to be matched in the comparing step; and an input determined by the number of digits. The call setup by transmitting the number entered for processing to the exchange at the same time as receiving the last digit If no matching sequence is found, a timeout process is performed to start call setup and complete the connection to the called party, and determine that dialing has been completed. A method comprising: 2. The network according to claim 1, wherein the network is a digital advanced mobile phone system (DA).
The method of claim 1, operating according to an MPS standard. 3. The method of claim 1, wherein the input number comprises a dual tone multiplex frequency tone. 4. The method according to claim 1, wherein said comparing step is performed in a telephone. 5. The method according to claim 1, wherein the pre-stored sequence list is stored in a memory of the telephone. 6. The method of claim 1, wherein the pre-stored sequence list is updated by a short message service function. 7. The method of claim 1, wherein the processing performed by the switching center includes processing to complete a connection to the called party. 8. The method according to claim 1, wherein said exchange functions as a private branch exchange. 9. At the start of the call setting step, if the matching sequence is not found, a call is completed by establishing a connection with an exchange in place of the "timeout" processing. The method of claim 1, wherein 10. A standard telephone, a transceiver station connected to the telephone, at least one base station for two-way wireless communication with the transceiver station, and an exchange connected to the at least one base station; The last digit of the telephone number is entered by the caller by comparing the means for detecting that the telephone has gone off-hook with a sequence of telephone numbers and a pre-stored list of digits. A fixed wireless network comprising: means for identifying a telephone number; and means for transmitting an input telephone number to the exchange for processing. 11. The fixed wireless network according to claim 10, wherein the input telephone number is stored in a memory of the telephone. 12. The fixed wireless network according to claim 10, wherein the sequence is the first three numbers of the input telephone number. 13. The fixed wireless network of claim 10, wherein the list is stored in a look-up table in a memory of the transceiver station. 14. The fixed wireless network according to claim 10, wherein said telephone number processing means includes means for completing a connection to said called party. 15. The exchange according to claim 10, wherein said exchange is a private branch exchange.
Fixed wireless network as described in.