KR100489893B1 - Wireless LAN Cellular System and Method for Operating - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a WLAN cellular system and a method of operating the same.

2. The technical problem to be solved by the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a wireless LAN cellular system and a method of operating the same, wherein a wireless subscriber using a wireless LAN performs a real-time voice call using a voice line of a cellular network.

3. Summary of Solution to Invention

According to an aspect of the present invention, there is provided a WLAN cellular system comprising: WLAN connection means for wirelessly connecting to a wireless terminal in a WLAN; And a wired connection with the wireless LAN access means through a wireless LAN and a cellular network protocol interworking function, and connected with a cellular network switch (MSC) to interwork the wireless LAN with the cellular network. Receiving a call setup control signal from the means, establishing a voice call in the same manner as in the cellular network, and including a WLAN access control means for performing a radio resource management function with the same function as a controller (RNC) of a wireless access network. .

4. Important uses of the invention

The present invention is used in a mobile communication system.

Description

Wireless LAN cellular system and its operation method {Wireless LAN Cellular System and Method for Operating}

The present invention provides a wireless LAN cellular system and a method of operating the same for enabling a wireless terminal user in a wireless local area network (WLAN) to support a voice call by accessing a cellular network like a cellular terminal using a microphone and a speaker. It is about.

While the commercialization of 3G cellular networks has slowed down recently, WLAN services are rapidly expanding.

Wireless LAN basically provides high-speed data service compared to 3G and existing cellular network, and its installation cost is also lower than existing cellular network. In addition, the Institute of Electrical and Electronics Engineers (IEEE) 802.11b network uses a 2.4 GHz Industrial Scientific and Medical Euipment (ISM) band to reduce the cost of frequency rental.

Meanwhile, 802.11a, which is an extended version of 802.11b operating at 5.5 GHz (U-NII band), can support high speeds of 6 to 54 Mbs by adopting an orthogonal frequency division multiplexing (OFDM) physical layer.

Meanwhile, in the existing 802.11a / b Mac (MAC: Media Access Control), time-bounded quality of service (hereinafter referred to as "QoS") is determined using a Point Cordination Function (PCF). To provide.

The PCF function, which is controlled by a Point Coordinator (PC), polls certain wireless terminals during the Contention Free Period (CFP) to guarantee a higher level of QoS than the Distribution Coordination Function (DCF) .However, Voice over Internet Protocol (VOIP) It does not guarantee real time transmission such as data. Therefore, the IEEE defines an 802.11e MAC (MAC) that improves the QoS function to the function of the existing 802.11 MAC (MAC).

In the 802.11e MAC, the HCF controlled by the EDCF function and the HC (Hybrid Coordinator), which extends the existing DCF function by imposing on the existing DCF (Distribution Coordination Function) and PCF (Point Cordination Function) functions. Coordination Function is defined to guarantee QoS in wireless network.

Meanwhile, a conventional wireless terminal, that is, a representative user of a notebook, uses VOIP (Voice of IP) to use a voice call. In order to provide VOIP services, devices such as Gateway, GatewayKeeper, and Location Server must be installed, and general wired and wireless subscribers can use ITU-T's H.323 or Internet Engineering Task Force (IETF). The call is established using a protocol such as SIP (Session Initiation Protocol), and voice data is transmitted according to the VOIP protocol set on the IP. In addition to the wired Internet, a technology and cellular network switch (MSC) for providing a voice call using VOIP to a mobile terminal subscriber using a cellular packet network such as GPRS (General Packet Radio Service) or UMTS (Universal Mobile Telecommunications Systems). There is an attempt to interwork a voice cellular network and a wired VOIP network using a gateway and a gateway.

1 is an exemplary configuration diagram showing an existing IEEE 802.11 network.

A plurality of wireless terminals (Mobile Station, STA1) (110) forms a basic service set (BSS) 130 controlled by a single coordination function (CF) using a laptop or a personal digital assistant (PDA), which is The AP is connected to another BSS through a distribution system (DS) 140 through an access point (AP) 120.

In the conventional WLAN having such a structure, a voice call is being transmitted using an existing IP-based Internet network using a VOIP function. At this time, the router, which is each transmission unit on each Internet, assumes a QoS guarantee protocol such as RSVP (Resource Reservation Protocol), but there is a problem that it is still incomplete and cannot guarantee QoS. In the wireless access section of the WLAN, a DCF function using a CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) protocol and an 802.11 Mac (MAC) providing a PCF function to guarantee low-level QoS provide real-time transmission of voice. There was a problem that could not be guaranteed.

In addition, a voice call line of a cellular network that completely guarantees QoS as a circuit switching method has not been fully utilized.

In addition, when a wireless LAN is interworked with a cellular network, there is a problem in that a wireless subscriber cannot be recognized in a cellular network like a conventional mobile communication subscriber.

The present invention has been proposed to solve the above problems, and an object of the present invention is to provide a wireless LAN cellular system and a method of operating the wireless subscriber using a wireless LAN to perform a real-time voice call using a cellular network. Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a WLAN cellular system comprising: WLAN connection means for wirelessly connecting to a wireless terminal in a WLAN; And a wired connection with the wireless LAN access means through a wireless LAN and a cellular network protocol interworking function, and connected with a cellular network switch (MSC) to interwork the wireless LAN with the cellular network. Receiving a call setup control signal from the means and establishing a voice call in the same manner as in the cellular network, and including a WLAN access control means for performing a radio resource management function with the same function as a controller (RNC) of a wireless access network. It is characterized by.

In addition, the present invention is characterized in that it further comprises a wireless terminal having a predetermined physical layer and a predetermined protocol function, and performs interworking with the cellular network and transmit / receive.

On the other hand, the method of the present invention, in a method of operating a WLAN cellular system, after wireless connection through a wireless terminal and a wireless accessor (AP) in the wireless LAN, authentication and location registration of a mobile subscriber using a mobility support protocol Location registration performing step of performing; A wireless LAN and a cellular network protocol interworking function are connected to the wireless LAN accessor by wire, and connected to the cellular network switch (MSC) to enable the wireless LAN to interwork with the cellular network. A voice call setup step of receiving a call setup control signal and setting up a voice call in the same manner as in the cellular network; And a radio resource management step of performing a radio resource management function with the same function as a controller (RNC) of a radio access network.

On the other hand, the present invention, by connecting the IEEE 802.11 network to the existing cellular network allows a wireless subscriber to access the cellular network using a wireless LAN (WLAN) in place of the wireless access network of the cellular network, using a microphone and a speaker 802.11e Mac (MAC) which improves QoS function of existing 802.11a / b MAC (MAC) to enable voice call and to guarantee real time voice call when wireless access network is replaced by WLAN. Adopted to ensure the real-time call of the voice in the wireless access network.

In addition, the present invention proposes a minimum control protocol model required for cellular network access so that a wireless subscriber can access a cellular network.

In addition, the present invention, when the wireless LAN interworking with the cellular network, the cellular network can recognize the wireless subscriber as a conventional mobile communication subscriber.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a diagram illustrating a network configuration for accessing a wideband code division multiple access (WCDMA) network and performing voice service using an IEEE 802.11e cellular network according to an embodiment of the present invention.

As shown in FIG. 2, a subscriber identity module (SIM) for mobile communication enables a wireless terminal user to access a cellular network like a cellular terminal using a microphone and a speaker to support voice calls in a wireless local area network. A wireless terminal equipped with a card, an access point (AP), and an access point controller (APC). To this end, the present invention has replaced the wireless access network of the second and third generation cellular network with 802.11 WLAN, and the Layer 2 protocol of the wireless access network to the existing WLAN (MAC) QoS (Qualiyt of Service) An enhanced 802.11e Mac (MAC) was used to transmit voice data in real time. Therefore, the wireless terminal has only layer 3 call processing and mobility management protocols ("CC" and "MM" in the case of WCDMA) of the cellular network on the upper part of the 802.11e MAC (MAC). The channel setting procedure of the communication network is omitted, and the control and voice data are transmitted in real time according to the HCF contention-based channel access (EDCF) function or the "HCF controlled channel access" function of 802.11e.

First, the wireless terminal performs authentication and location registration of the mobile subscriber using the installed SIM card and Layer 3 mobility support protocol, and uses the function of the "HCF controlled channel access" of 802.11e as a call setup request message. To the AP, which in turn passes it to the APC. At this time, the message delivered to the APC is delivered to Layer 3 of the core network (CN: MSC / VLR) of the cellular network and goes through a basic voice call setup process.If the call setup process is successful, the APC and the core network are performed as in the cellular network. The channel is configured with the same interface between the AP and the AP and the radio terminal, and reserves radio resources and transmits data using the EDCF function or the "HCF controlled channel access" function. The voice data transmitted to the 802.11e MAC of the wireless terminal is transferred to the codec, and the voice is sampled from the microphone and transmitted in the reverse direction.

In addition, the present invention allows to use the 802.11 network as an outdoor cellular network, so that a wireless terminal user of a wireless LAN (WLAN) equipped with a SIM card can make a voice call in the same way as a cellular terminal user using a microphone and a speaker. do.

The present invention will be described in more detail with reference to FIG. 2 as follows.

In the present invention, the wireless terminal 240 and the wireless access network 200 are redesigned so that the wireless terminal subscriber using the WLAN can access the cellular network and receive the same voice call service as the cellular subscriber.

First, in the present invention, the wireless terminal 240 is equipped with a SIM (Subscriber Indentification Module) module 210 for user authentication so that the wireless terminal 240 can be authenticated in the same manner as the mobile subscriber. Therefore, regardless of any laptop, PDA, or mobile terminal, if only the SIM 210 module is present in the wireless terminal 240, the same subscriber can be authenticated. In addition, the audio function provided by the laptop is used for voice communication, and a general microphone or speaker (MIC & SPK) 220 is used.

Meanwhile, in the present invention, the RNC is replaced with the APC 280 in the radio access network (UTRAN) 200 of the cellular network or the RNC is restarted to include the function of the APC 280 in the existing RNC 270 function. In this case, both the RNC 270 and the APC 280 are connected to the MSC / VLR 290 of the core network CN with the same interface specification as the existing cellular network.

In the present invention, the Node B 250 has replaced the AP 260, which is a QoS enhancement to the existing AP, that is, a QAP (QoS enhanced Access Point) over 802.11e. Therefore, the radio access section is operated according to the 802.11e MAC (MAC) protocol which improves QoS to the 802.11 MAC (MAC) function in place of the protocol used in the existing cellular network.

3 is an exemplary configuration diagram of a conventional cellular network WCDMA control plane protocol, and illustrates a structure diagram of a WCDMA control plane protocol in an existing cellular network for voice call service.

4 is an exemplary configuration diagram of an existing cellular network WCDMA user plane protocol, and illustrates a structure diagram of a WCDMA user plane protocol in a cellular network for voice call service.

FIG. 5 is a diagram illustrating a control plane protocol according to an embodiment of the present invention, and illustrates a control plane protocol architecture for accessing a WCDMA network using an 802.11e cellular network.

FIG. 6 is a diagram illustrating a user plane protocol according to an embodiment of the present invention, and illustrates a user plane protocol structure for accessing a WCDMA network using an 802.11e cellular network to provide a voice service.

The WLAN cellular system and its operation method according to the present invention have proposed a network model for connecting a WLAN to a cellular network so that a wireless terminal of the WLAN can access a cellular network and receive a voice call service.

The WLAN cellular system and its operation method according to the present invention will be described in more detail with reference to FIGS. 2 to 6 as follows.

In the present invention, only the interface between the Node B 250 and the mobile terminal (MT) 230, that is, the Uu interface has been replaced with the WLAN section used in 802.11. Accordingly, the PDCP, RRC, RLC, and MAC protocols of Layer 2 or lower, which are used in a wireless access section, of the protocol of the wireless terminal are omitted, and instead, the 802.11e MAC protocol is used.

Meanwhile, only the Layer 3 Call Control (CC) protocol and the Mobility Management Protocol (MM) are adopted to enable the wireless terminal to establish a call with the MSC of the cellular network. In addition, RRM (Radio Resource Management) function has been added for resource management in the added WLAN.

In the present invention, the AP 260 is operated according to a wireless terminal, an 802.11 physical layer, and an 802.11e MAC (MAC) and has a wired connection with the APC 280. It can also transmit real-time data and control signals to wireless terminals and access them to other Internet networks.

The APC 280 is connected to the AP 260 and maintains information necessary for interworking with the cellular network and is connected to the MSC / VLR 290 with the same connection standard as the cellular network and the RNC 270.

On the other hand, the use of the service in the present invention as described above consists of a call setup process using a control signal and a voice call process after call setup. The present invention uses a hybrid coordination function (HCF) function of the 802.11e MAC (MAC) in the wireless access section using the 802.11e for the transmission of the control signal, in particular the "HCF controlled channel access" function or PCF of the HCF function (Point Coordination Functoin) function, and use "HCF controlled channel access" function, Point Coordination Functoin (PCF) function, or HCF contention-based channel access (EDCF) function for real time transmission of voice data after call setup This mapping is done by the MAC Scheduler.

7 is a flowchart illustrating a WCDMA voice call setup process in Layer 3 according to the present invention.

As shown in FIG. 7, Layer 3 control messages are sent in 802.11e MAC (MAC) frames.

8 is a flowchart illustrating a process of providing a voice service by accessing a WCDMA network using an 802.11 cellular network according to the present invention, and a simple 802.11e STA-initiated using a "HCF controlled channel access" function and a wireless LAN; An example of a WCDMA network call establishment and call release process in a cellular network and a call up to voice data transmission using a "HCF contention-based channel access (EDCF)" function and a "Burst Ack" mechanism are shown.

8 shows a signal and data transmission process between a STA and a hybrid coordinator (HC).

First, the layer 3 control message of the cellular protocol transmitted from the wireless terminal to the AP in the call setup process is transferred to the call control protocol (CC) and the mobility management protocol (MM) of the MSC through the APC to form a call. . At this time, a layer 3 message caused by the wireless terminal is transmitted in an 802.11e MAC frame. And, like a PC (Point Coordinator) in a typical 802.11 WLAN, the function of the HC is generally considered to be included in the function of the AP. In FIG. 8, it is assumed that the call setup procedure of the WLAN is already performed.

First, the wireless terminal 800 must perform a location registration procedure in order to use a cellular network access service, and uses a "HCF controlled channel access" function to transmit a location registration request message. 802.11e MAC (MAC), as in the 802.11 MAC (MAC) basically occurs by repeating the CP (Contention Period) and CFP (Contention Free Period) periodically, which is controlled by the HC, not the PC. However, 802.11e MAC (MAC) additionally sends a "CC (Controlled Contention) Control Frame" in order to cause the HC (810) to cause a Controlled Contention Interval (CCI) regardless of CP or CFP, The wireless terminal 800 allows a resource for wireless transmission to be reserved. At this time, the CC includes the number of Controlled Contention Opportunities (CCOPs) in the CCI, that is, "Nccop" and a duration time value of each CCOP (821).

Meanwhile, the wireless terminal 800 waits to receive the "CC Control Frame" caused by the HC 810 in order to transmit the location registration control message. When the "CC Control Frame" is received, a "RR (Reservation Request) frame" is transmitted to the HC 810 to reserve a radio resource. The transmitted "RR Frame" includes a Traffic ID (TID) and a Transmission OPportunity (TXOP) duration value (822).

The HC 810 receives "RR Frame" from several wireless terminals 800 during CCI, receives resource reservation contents of each wireless terminal 800, and transmits the "CC Control Frame" to the next CCI within the available resource limit. Notifies that the radio resource is reserved to the wireless terminal 800 by using. At this time, the wireless terminal 800 confirms that the radio resource reservation request has been approved with its "AID" value in the "Feedback Field" of the "CC Control Frame" (823).

The HC 810 transmits a "(QoSData +) CF-Poll" message to the wireless terminal 800 that has approved "RR" to give a transmission opportunity (TXOP), that is, a wireless transmission opportunity (824). Upon receiving this, the wireless terminal 800 transmits a location update message to the AP 810 using the “QoSData” frame (825). The AP 810 again forwards this message to the APC, which in turn sends the MSC's mobility management protocol. The control message (Location Update Accept) message responded from the MSC is passed back to the AP 810 via the APC, and the forwarded message is transmitted through "(QoS Data +) CF-Poll + CF-Ack Frame (Location Update Accept)". It is transmitted to the wireless terminal 800 (826). In this process, the mobility management protocol of the MSC can perform a mobile subscriber authentication procedure and is omitted in this flowchart.

If the mobile terminal 800 can make a voice call at a desired time point after the location registration procedure, it is assumed in this flowchart that the current TXOP ends and requests call setup for the voice call again (827). The HC 810 sends a "CF-End Frame" to end the current TXOP (828)

In order to make a voice call, a call control (CC) protocol of a wireless terminal requires a radio resource setting to a wireless access network of a WLAN. To this end, the wireless terminal 800 performs a procedure of steps 822 to 825 again and receives a TXOP. The wireless terminal 800 assigned the TXOP transmits a "CM Service Request" message using the "QoS Data Frame". The message delivered to the AP 810 is delivered to the call control protocol (CC) layer of the MSC via the APC. At this time, the MSC's call control (CC) protocol may request an authentication procedure of the mobile subscriber (829 to 835).

The authentication of the wireless subscriber is completed and the call control (CC) protocol of the wireless terminal sends a "Setup" message for voice call setup to the call control (CC) protocol of the MSC, and the MSC responds to the "Call Proceeding". A message is sent to the wireless terminal 800 to inform that call setup is in progress. After that, the MSC's call control (CC) protocol transmits an "Alert" and a "Connect" message to inform the wireless terminal 800 that a call setup with the other party has been made, and the wireless terminal 800 sends a "Connect Ack" message. In response, the voice call setup is completed and the current TXOP is terminated. The Layer 3 control message is transmitted by the 802.11e MAC frame in the same manner as the location registration request message is transmitted (836 ~ 843).

When the voice call is set up, the voice call is possible as in the cellular network. In the present invention, 802.11e MAC (MAC) is assumed to guarantee a real-time voice call and transmitted using the "HCF controlled channel access" function or the "HCF contention-based channel access (EDCF)" function of 802.11e.

On the other hand, unlike the 802.11 MAC (MAC) that must respond with "ACK" to every frame transmitted in transmitting the voice data, the characteristics of the voice data that allow some loss and do not require "ack" Consider using the "Burst Ack" mechanism proposed by 802.11e. The "Burst Ack" mechanism defined in 802.11e continuously transmits a series of MAC frames in a "SIFS" cycle, and an "Ack" for it transmits a "Burst ACK Request" if necessary, thereby transmitting a frame. It responds with "ACK" in one frame.

In order to use the "Burst Ack" mechanism, the wireless terminal 800 and the AP 810 exchange a "Define Burst Ack QoS Action request / response frame" at the same time as the voice call setup.

Meanwhile, at the same time as the voice call setup, the wireless terminal 800 sends out the received frame to the speaker through the codec and transmits the sampled data from the microphone input to the AP 810 to enable voice communication (844).

If the voice call is to be terminated, call setting of the wireless access network should be reserved in order to transmit a call release message (Disconnect) again, and the call setting process is the same as that of 821 to 824 (845 to 848).

When the allocation of the radio resource is made, the wireless terminal 800 transmits a call release message to the call control (CC) protocol of the MSC, where the MSC responds with a release message to accept the call release. Finally, the wireless terminal 800 transmits the successful release of the call in a "Release Ack" message, and then the AP 810 terminates the current TXOP. At this time, radio resources allocated to the radio access network and the MSC are released (849 to 853).

Meanwhile, in the present invention, a SIM module is mounted in order to be recognized as a mobile subscriber by accessing a mobile cellular network using a wireless terminal.

In addition, the wireless terminal, since the existing 802.11e MAC (MAC) plus the QoS function to the function of the existing 802.11 MAC (MAC) can be connected to the existing WLAN to support the necessary services. This dual mode support and selection can be set automatically without user intervention. This type of service may be broadcast using a beacon frame. The present invention described above does not depart from the spirit of the present invention for those skilled in the art to which the present invention pertains. Various substitutions, modifications, and changes are possible without departing from the scope of the present invention and are not limited by the above-described embodiments and the accompanying drawings.

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As described above, the present invention enables 802.11 wireless LAN subscribers, which are rapidly spreading recently, to access cellular networks and make voice calls with cellular network subscribers, and wireless subscribers and cellular network subscribers do not use VOIP. Voice call is effective.

In addition, the present invention, if the wireless subscriber is equipped with a SIM module provides a service mobility so that the subscriber can receive the same voice call service not only in the cellular network but also in the WLAN, the cellular network required for the cellular network and WLAN connection The control message can be transmitted within the time limit of each message timer, and when the voice call is set up, the voice can be transmitted in real time.

1 is a configuration example showing an existing IEEE 802.11 network,

2 is a configuration diagram of an embodiment of a network according to the present invention;

3 is an exemplary configuration diagram of an existing cellular network WCDMA control plane protocol;

4 is an exemplary configuration diagram of an existing cellular network WCDMA user plane protocol;

5 is a structural diagram of an embodiment showing a control plane protocol according to the present invention;

6 is a structural diagram of an embodiment showing a user plane protocol according to the present invention;

7 is a flowchart illustrating a WCDMA voice call setup process in Layer 3 according to the present invention;

8 is a flowchart illustrating a process of providing a voice service by accessing a WCDMA network using an 802.11 cellular network according to the present invention.

* Explanation of symbols for the main parts of the drawings

200: wireless access network 210: SIM

220: MIC & SPK 230: MT

240: STA 250: Node B

260: AP 270: RNC

280: APC 290: MSC / VLR

Claims (18)

In a WLAN cellular system, WLAN connection means for wireless connection with a wireless terminal in a WLAN; And The wireless LAN access means connects to the wireless LAN access means via a wireless LAN and cellular network protocol interworking function and connects to the cellular network switch (MSC) to interwork the wireless LAN with the cellular network. WLAN access control means for receiving a call setup control signal from the mobile station and setting up a voice call in the same manner as in the cellular network, and performing a radio resource management function with the same function as a controller (RNC) of a wireless access network. WLAN cellular system comprising a. The method of claim 1, The wireless terminal having a predetermined physical layer and a predetermined protocol function and performing interworking and transmission / reception with the cellular network. WLAN cellular system further comprising. The method according to claim 1 or 2, The WLAN connection means, Wireless LAN cellular system characterized in that the wireless connection to the wireless terminal, and the wired connection with the access control means using an IEEE (Institute of Electrical and Electronics Engineers) 802.11 physical layer and 802.11e MAC (MAC) function. The method according to claim 1 or 2, The wireless LAN access control means, It is connected to the switch which is the core network (CN: MSC / VLR) of the cellular network so that the WLAN can be interworked with the cellular network, and the core network in the same manner as the wireless access network and the switching period interface (Iu-CS). To establish a voice call in the same manner as in the cellular network by receiving call setting control signals from the plurality of WLAN access means, and to perform a radio resource management function with the same function as the RNC of the wireless access network. Wireless LAN cellular system characterized by. The method of claim 3, wherein The wireless terminal, Layer 2 performing IEEE 802.11 physical layer, 802.11e MAC layer protocol function, mobility management protocol (MM) and call control (CC) protocol function for location registration and call setup in the cellular network. And a layer 3 performing the call, reproducing the data transmitted from the other party through the speaker after the call is set up, and transmitting the sampled data through the microphone. The method of claim 5, wherein The wireless terminal, The Layer 3 protocol function of the cellular network remains in Layer 3 for call establishment and location registration with the cellular network, and 802.11 MAC / 802.11 in Layer 2 for the cellular network access. e Wireless LAN cellular system characterized by including the SIM module to operate using a MAC (MAC), the same as the cellular network subscriber. In the method of operating a WLAN cellular system, Performing a location registration step of performing authentication and location registration of a mobile subscriber using a mobility support protocol after wireless connection through a wireless terminal and an access point (AP) in the WLAN; A wireless LAN and a cellular network protocol interworking function are connected to the wireless LAN accessor by wire, and connected to the cellular network switch (MSC) to enable the wireless LAN to interwork with the cellular network. A voice call setup step of receiving a call setup control signal and setting up a voice call in the same manner as in the cellular network; And Radio resource management step of performing a radio resource management function with the same function as the controller (RNC) of the radio access network Method of operation of a WLAN cellular system comprising a. The method of claim 7, wherein The location registration step, A reception waiting step of waiting for the wireless terminal to receive a "CC Control Frame" caused by the cellular network in order to transmit a location registration control message; A radio resource reservation step of transmitting a "RR (Reservation Request) frame" to the cellular network to reserve radio resources when receiving the "CC Control Frame"; The cellular network receives the "RR Frame" from the wireless terminal for a predetermined period of time, receives the resource reservation contents of the wireless terminal, and uses the "CC Control Frame" transmitted within the next predetermined period within the available resource limit. A radio resource reservation notification step of informing the terminal of the radio resource reservation; Granting a radio transmission opportunity to the wireless terminal for which the cellular network has approved the "RR Frame"; And A transmission step of transmitting a location update message to the cellular network by the wireless terminal given the wireless transmission opportunity; Method of operation of a WLAN cellular system comprising a. The method of claim 8, The reception waiting step, The wireless terminal uses the "HCF controlled channel access" function to perform the location registration procedure using the cellular network access service, 802.11e MAC (MAC) is basically CP (Contention Period) as in 802.11 MAC (MAC) ) And CFP (Contention Free Period) occur periodically and repeatedly, and the 802.11e MAC (MAC) is additionally "Controlled (CC) irregularly to cause Controlled Contention Interval (CCI) regardless of CP or CFP. Contention) Control Method of the WLAN cellular system, characterized in that for transmitting a "Control Frame." The method of claim 9, The CC (Controlled Contention), And a number of Controlled Contention OPportunities (COPOPs) in the CCI, that is, "Nccop" and a duration time value of each CCOP. The method of claim 8, The radio resource reservation step, The transmitted “RR Frame” includes a TID (Traffic ID) and a TXOP (Transmission OPportunity) period value, wherein the wireless terminal reserves a resource for transmission. The method of claim 8, The radio resource reservation notification step, And the wireless terminal confirms that the radio resource reservation request has been approved with its identifier value in the " Feedback Field " of the " CC Control Frame. &Quot; The method of claim 8, The transmitting step, The APC transmits a message received by an access point (AP) of the cellular network to an access point controller (APC), and the APC transmits back to the mobility management protocol of the cellular network exchange, and receives a response message from the exchange. The WLAN is transmitted to the AP via the APC, and the transmitted message is transmitted to the wireless terminal through "(QoS Data +) CF-Poll + CF-Ack Frame (Location Update Accept)". How cellular systems work. The method of claim 7, wherein The voice call setting step, Requesting a radio resource setting to a wireless access network of the wireless LAN by a call control (CC) protocol of the wireless terminal for a voice call and receiving a TXOP (Transmission OPportunity); A wireless subscriber authentication step of authenticating the wireless subscriber by transmitting a "CM Service Request" message using the "QoS Data Frame" by the wireless terminal assigned the TXOP; After the authentication of the wireless subscriber is completed, the call control (CC) protocol of the wireless terminal sends a "Setup" message for establishing a voice call to the call control (CC) protocol of the exchange, and the exchange responds to " Transmitting a Call Proceeding "message to the wireless terminal to notify that call setup is in progress; Informing the wireless terminal that call establishment with the other party is established by a call control (CC) protocol of the exchange transmitting a "Alert" and a "Connect" message; And The wireless terminal responding to the "Connect Ack" message to notify that the voice call setup is completed and ending the current TXOP; Method of operation of a WLAN cellular system comprising a. The method of claim 14, The wireless subscriber authentication step, The message transmitted from the wireless terminal to the access point (AP) is transmitted to the call control protocol (CC) layer of the exchange via an access point controller (APC), where the call control (CC) protocol of the exchange is authenticated by the mobile subscriber. (Authentication) A method for operating a WLAN cellular system characterized in that it may require a procedure. The method of claim 14, The voice call, A method of operating a WLAN cellular system, which uses a "HCF controlled channel access" function, a point coordination functoin (PCF) function, and an "HCF contention-based channel access (EDCF)" function for real-time transmission of voice data. The method of claim 16, Real time transmission of the voice data, And a " Burst Ack " mechanism between the wireless terminal and the AP when transmitting voice data. The method according to any one of claims 7 to 17, The wireless terminal, A method of operating a WLAN cellular system, which operates in a dual mode that can be operated in conjunction with the cellular network and can be operated by accessing an existing WLAN.