The objectives and features of the present invention will become more apparent from the consideration of the following detailed description taken in conjunction with the accompanying drawings in which:
Referring now to
The IP telephone communication system at least includes a plurality of Access Points AP1 to APN (N is an integer) and a plurality of (mobile) stations STA to STN under control of each of the Access Points AP1 to APN.
Each of the Access Points AP1 to APN determines whether stations (STA1 to STAN) having established communication lines for IP telephone communication include a station STAN in a silent state (where IP communication is not conducted). If such a silent station STAN exists, the system conducts pseudo IP telephone communication corresponding to a state in which the silent station STAN conducts IP telephone communication. It is hence possible to set all stations (STA1 to STAN) having established communication lines for IP telephone communication with associated Access Points (AP1 to APN) to a state in which the stations are virtually conducting IP telephone communication. Therefore, even in a situation in which the stations (STA1 to STAN) having established communication lines for IP telephone communication with associated Access Points (AP1 to APN) include a station in the silent state, it is possible to determine connectibility of a station for IP telephone communication with high reliability. Referring next to the accompanying drawings, description will be given in detail of the IP telephone communication system according to the embodiments.
First, referring to
The system includes a plurality of Access Points AP1 to APN (N is an integer) and a plurality of stations STA1 to STAN under supervision of each of the Access Points AP1 to APN as shown in
Each of the Access Points AP1 to APN establishes a communication line of IP telephone communication with the stations STA1 to STAN to communicate data and information with other Access Points. Referring next to
Each Access Point includes a communication module 201, a control module 202, a storage section 203, and an antenna 204 as shown in
The module 201 establishes IP telephone communication with one of the stations STA1 to STAN to communicate data over a particular frequency. The module 201 also communicates information with another Access Point.
The module 202 supervises operations in an Access Point. The section 203 stores various setting values and temporarily saves information communicated via the module 201. The setting values include, for example, a maximum band state that the Access Point can have, a radio channel, and a Service Set IDentifier (SSID).
Referring now to
Each Access Point conducts a pseudo IP telephone communication. The pseudo IP telephone communication is a control operation to make a situation where all the stations that possess communication lines conduct IP telephone communication. The control operation will next be described by referring to
First, an Access Point (AP1 to APN) determines whether the stations (STA1 to STAN) having established communication lines include a station STAN in a silent state (step S1).
If it is determined that there does not exist such a silent station STAN (no in step S1), the Access Point terminates the processing (End). Otherwise (yes in step S1), the Access Point creates pseudo IP packet data corresponding to a state in which the silent station STAN carries out IP telephone communication (step S2). The Access Point then sends the data to the network NW on the uplink side. This sets the stations having established communication lines with the Access Point to a state in which the stations are conducting virtual IP telephone communication.
Whether the stations having established communication lines for IP telephone communication include a station in the silent state is determined using, for example, a first determination method as below.
An Access Point (AP1 to APN) analyzes IP packet data of the communication protocols such as Session Initiation Protocol (SIP) and Real-time Transport Protocol (RTP) sent from each station having established the communication line for IP telephone communication to examine a state of transmission of the IP packet data to determine whether the pertinent station is transmitting IP packet data of IP telephone communication. If it is determined that the station is transmitting other than the IP packet data of IP telephone communication, it is determined that there exists a station STAN in the silent state.
The first method is applicable to a situation in which the IP packet data is not encrypted. If the data is encrypted, there can be used a second determination method as below.
A station (STA1 to STAN) creates, in a Type Of Service (TOS) field of the IP header, IP packet data including information to determine whether IP telephone communication is to be carried out and then sends the data to the associated Access Point (AP1 to APN). When the data is received, the Access Point analyzes the TOS field to examine the state of transmission of the data. If it is determined that the station is transmitting other than IP packet data for IP telephone communication, the Access Point determines that there exists a station in the silent state.
In this connection, the Access Point conducts the control operation shown in
In the maximum band state, for example, if the first Access Point AP1 receives a association request for IP telephone communication from an additional station STA not having established a communication line for IP telephone communication as shown in
If it is determined that the band is not reserved, the first Access Point AP1 rejects the association request for IP telephone communication from the additional station STA (step S13).
Each of the Access Points AP1 to APN carries out the control operation shown in
The method of determining whether the predetermined band is securable on the network is not particularly limited. That is, there may be employed any determination method if it is possible to determine, for the network in the maximum band state, whether the band is securable on the network according to information obtained when the trial IP packet data is transmitted
In the IP telephone communication system, the system favorably controls operations such that the IP packet data used for the pseudo IP telephone communication and employed for the trial IP telephone communication are sent to the network with a priority level lower than that of the IP packet data actually being transmitted through the IP telephone communication. As a result, even if the pseudo IP telephone communication or the trial IP telephone communication is carried out, the load imposed on the network can be mitigated. Also, the IP packet data actually being transmitted through the IP telephone communication on the network can be transmitted with a higher priority level. Therefore, it is possible to reduce the influence on the actually communication of the IP packet data through the IP telephone communication. In addition, since the check for connectibility of the additional station (STA) for the IP telephone communication is made under a severe environment, the result of the determination of connectibility for the IP telephone communication is attainable with further higher reliability.
As a method of controlling operation such that the IP packet data used for the pseudo IP telephone communication and employed for the trial IP telephone communication are sent to the network with a priority level lower than that of the IP packet data actually being transmitted through the IP telephone communication, there may be adopted a method in which, for example, IP packet data including priority information indicating a priority level is transmitted to the network.
Next, description will be given of a second embodiment.
An IP telephone communication system is constructed in the form of a wireless LAN mesh network as shown in
Referring now to
The communication system includes a mesh connection manager device 1, a mesh portal unit 10, a plurality of mesh Access Points A to F, and a plurality of stations STA1 to STAN.
In the communication system, the mesh portal 10, the Access Points A to F, and the stations STA1 to STAN form a radio LAN mesh network NW. The mesh network includes radio networks between the stations STA1 to STAN and the Access Points A to F and relay networks between the Access Points A to F and between the mesh portal and the Access Points A and B. The radio networks and the relay networks favorably use mutually different radio channels to thereby prevent interference between radio waves.
It is assumed in the embodiment that the wireless LAN mesh network NW conforms to the definitions of functional elements prescribed by IEEE802.11s. The functional elements to configure the relay network in the form of a mesh are called mesh points. Among the mesh points, a mesh point providing a function of a Access Point is called a mesh Access Point (A to F) and a mesh point providing a gateway function for an external network such as ethernet (registered trademark) is called a mesh portal (10). The mesh portal (10) may include a function similar to that of the mesh Access Point (A to F).
Referring to
The connection manager 1 is an information processing unit to control the mesh Access Points A to F and the mesh portal 10 configuring the wireless LAN mesh network. As shown in
The module 301 communicates information with the Access Points A to F and the mesh portal 10. In the information communication, the communication module 301 may employ a desired communication mode only if information can be communicated therebetween. For example, information may be transmitted through wired communication or wireless communication.
The module 302 supervises operations in the mesh connection manager 1. When a connection judge request of IP telephone communication for an additional station STA additionally desiring IP telephone communication is received from one of the mesh Access Points A to F or the mesh portal 10, the module 302 issues a control indication to carry out trial IP telephone communication between the Access Point or the mesh portal 10 and a destination station STA as the destination of IP telephone communication of the additional station STA or the mesh portal 10. Thereafter, the module 302 receives information of communication quality obtained as a result of the trial IP telephone communication conducted by the mesh Access Point or the mesh portal 10. Based on the communication quality information, the module 302 determines connectibility of the IP telephone communication. The module 303 controls connection information of the mesh Access Points A to F on the mesh network or the stations STA1 to STAN coupled with the mesh portal 10. On the basis of the connection information of the module 303, the module 302 can recognize the Access Points A to F on the mesh network or the stations STA1 to STAN coupled with the mesh portal 10.
Referring next to
In the second embodiment, each of the Access Points A to F includes a mesh point controller 410 and an access point controller 420 as shown in
The module 411 carries out trial IP telephone communication using dummy IP packet data. When an association request for IP telephone communication is received from an additional station STA not having established IP telephone communication, the module 411 issues a connection judge request for IP telephone communication to the mesh connection manager 1. According to a control indication from the connection manager 1, the module 411 communicates the dummy IP packet data with a mesh Access Point (A to F) or the mesh portal 10 connected to a destination station STA as the communication destination of the additional station STA to thereby conduct the trial IP telephone communication. As a result of the communication, the module 411 collects information such as delay, deviation, and a packet loss taking place during the communication, as communication quality information required to evaluate quality of the IP telephone communication. The module 411 then delivers the information to the mesh connection manager 1.
Like the module 411, the module 412 conducts IP telephone communication using the dummy PI packet data and controls operations similar to that shown in
Next, description will be given of internal structure of the mesh portal 10 by referring to
The mesh portal 10 includes a mesh point control module 510 and an external network control module 520 as shown in
In this connection, the module 511 conducts control in a way similar to that of the module 411 of the mesh Access Point (A to F) shown in
The module 512 carries out pseudo IP telephone communication in addition to the control operation of the module 412 of the mesh Access Point (A to F) shown in
Referring next to
In the following description of processing, as can be seen from
First, the mesh Access Points A to F and the mesh portal 10 configuring the mesh network carry out control operation similar to that shown in
As a result, each station (STA1 to STAN) having established a communication line for IP telephone communication with one of the Access Points A to F or the mesh portal 10 is set to the state in which the station is virtually communicating data through IP telephone communication, and hence the mesh network can be set to the maximum band state.
The maximum band state is a band state established when all Access Points A to F and the mesh portal 10 on the mesh network conduct a control operation similar to that shown in
In the maximum band state of the mesh network, the additional station STA sends to the Access Point F an association request for IP telephone communication with the destination station STA coupled with the external network (step S21).
When the association request is received, the Access Point F delivers a connection judge request of IP telephone communication associated with the association request to the mesh connection manager 1 (step S22).
After having received the connection judge request, the manager 1 transmits a control indication to carry out trial IP telephone communication to the Access Point F connected to the additional station STA as the request source and the mesh portal coupled with the destination station STA as the destination of the request (step S23).
When the control indication to carry out the trial IP telephone communication is received from the manager 1, the Access Point F and the mesh portal 10 create trial IP packet data including dummy data capable of identifying that the communication is IP telephone communication on the mesh network by setting, for example, a message format conforming to Real-time Transport Protocol (RTP) or RTP Control Protocol (RTCP) and a Type Of Service (TOS) field of the IP packet. The portal 10 and the Access Point F mutually communicate the trial IP packet data via a relay network with each other and resultantly gather communication quality information such as delay, deviation, a packet loss required to evaluate quality of the IP telephone communication (step S24).
The Access Point F and the mesh portal 10 send the communication quality information to the mesh connection manager 1 (step 25).
The manager 1 receives the information from the Access Point F and the mesh portal 10 to determine, based on the information, whether the IP telephone communication satisfies predetermined communication quality. If it is determined that the communication satisfies the predetermined quality, the manager 1 allows the connection for IP telephone communication. Otherwise, the manager 1 rejects the connection for IP telephone communication (step 26). Thereafter, the manager 1 delivers, in response to the connection judge request, the connection judge result to the Access Point F (step S27).
According to the judge result from the manager 1, the Access Point F determines whether the association request from the station STA is accepted (step S28). If the judge result indicates that the connection is rejected, the Access Point F rejects the association request. If the judge result indicates that the connection is granted, the Access Point F allows the association request.
As above, in the embodiment of an IP telephone communication system, each of the mesh Access Points A to F and the mesh portal 10 on the wireless LAN mesh network NW determine whether the stations (STA1 to STAN) having established a communication line for IP telephone communication with one of the mesh Access Points A to F or the mesh portal 10 include a station STAN in the silent state not communicating data through IP telephone communication. If it is determined that such a station STAN in the silent state is included, the Access Points A to F and the portal 10 each carry out the pseudo IP telephone communication corresponding to a state in which the station STAN is communicating data through IP telephone communication. This resultantly leads to a state in which each of the stations STA1 to STAN having established a communication line for IP telephone communication on the mesh network is virtually communicating data through IP telephone communication to thereby set the mesh network to the maximum band state.
In the maximum band state of the mesh network, if the station STA not having established a communication line for IP telephone communication issues an association request for IP telephone communication, data is communicated through trial IP telephone communication between the Access Point F coupled with the station STA and the mesh portal 10 connected to a destination station STA as the destination of IP telephone communication with the station STA. The Access Point F and the portal 10 collect communication quality information resultant from the operation to communicate data through trial IP telephone communication to send the information to the unit 1. On the basis of the communication quality information from the Access Point F and the portal 10, the managing unit 1 determines connectibility of the station STA for IP telephone communication.
Resultantly, in the maximum band state of the wireless LAN mesh network, it is possible to determine connectibility of the station STA desiring to additionally conduct IP telephone communication for IP telephone communication. Therefore, even if the stations (STA1 to STAN) having established communication lines for IP telephone communication on the mesh network include a station STAN in the silent state, the connectibility for IP telephone communication can be determined with high reliability.
Also, even if the station STAN in the silent state communicates data through IP telephone communication after the connection of the station STA for IP telephone communication is granted, since predetermined communication quality can be guaranteed on the mesh network in any situation, it is possible under any condition to guarantee predetermined service quality for all stations allowed for the connection for IP telephone communication.
In the determination of connectibility for IP telephone communication in step S26, the mesh connection manager 1 determines, on the basis of the communication quality information from the Access Point F and the portal 10, whether the communication satisfies the predetermined communication quality. The determination may be conducted, for example, as below. The communication states such as delay, deviation, and a packet loss on the mesh network as a result of the trial IP telephone communication are compared with reference communication states such as a delay time, a deviation ratio, and a packet loss ratio beforehand set in the manager 1. If it is determined that the communication states of the mesh network satisfactorily match the reference communication states, the manager 1 determines that the predetermined communication quality is satisfied. If the communication states of the mesh network do not satisfy the reference communication states, the manager 1 determines that the predetermined communication quality is not satisfied. However, the determination method is not restricted by the embodiment. There may be employed any determination method only if it is possible to determine, according to the communication quality information received from the Access Point F and the mesh portal 10, whether the predetermined communication quality is satisfied.
In the determination of connectibility for IP telephone communication in step S28, the Access Point F determines, according to the connectibility judge result from the manager 1, whether the association request of the station STA for IP telephone communication is granted. However, the determining method is not restricted by the embodiment. It is also possible to determine connectibility of the station STA for IP telephone communication by use of various conditions.
For example, the Access Point F manages the number of stations that can be connected to the Access Point F and that can establish communication lines for IP telephone communication with the Access Point F. Assume that connectibility for IP telephone communication is determined according to the number of stations. By use of, for example, the judge result of connectibility according to the number of stations and the judge result received from the manager 1, if it is determined that the connection of the station STA for IP telephone communication is possible, the association request of the station STA for IP telephone communication is granted. Therefore, it is possible to determine connectibility of the station STA for IP telephone communication in the whole wireless intervals of the mesh network.
In the processing of the second embodiment, when the association request for IP telephone communication is received from the station STA, the Access Point F sends a connection judge request of IP telephone communication to the mesh connection manager 1. However, the connection judge request may be transmitted at timing other than that described above. The request may be delivered to the manager 1 at desired point of time, for example, at prior confirmation of connectibility of IP telephone communication in consideration of handover of the station STA.
Also, in conjunction with the operation of the IP telephone communication system, description has been given of connectibility for IP telephone communication between the additional station STA coupled with Access Point F and the destination station STA linked with an external network. Data is communicated through trial IP telephone communication between the Access Point F and the mesh portal 10 via the relay network to thereby determine connectibility of the additional station STA for IP telephone communication. However, data may be communicated therebetween via various routes on the relay network to obtain communication quality information items resultant from the communication. The communication quality information items of the mutually different routes are compared with each other. According to results of the comparison, the system conducts a control operation to acquire an optimal relay network route having the highest communication quality.
In a situation in which the IP telephone communication is conducted according to priority assigned to each IP packet data in the mesh network under control of the IP telephone communication system, it is favorable that the IP packet data for the pseudo IP telephone communication and that for the trial IP telephone communication are fed to the mesh network with a priority level less than that of the IP packet data actually being transmitted through IP telephone communication. As a result, even if the pseudo IP telephone communication and the trial IP telephone communication are carried out, the load imposed on the mesh network can be reduced. Since IP packet data being transmitted in advance through IP telephone communication on the mesh network can be delivered with a higher priority level, it is possible to mitigate influence upon the transmission of IP packet data actually being delivered through IP telephone communication. The check for connectibility of the additional station STA for IP telephone communication is more severely carried out, and hence there is obtained the judge result of connectibility for IP telephone communication with higher reliability.
Next, description will be given operation of the third embodiment.
In the second embodiment, as can be seen from
First, referring to
The IP telephone communication system includes a mesh connection managing unit 1, a mesh portal 10, a plurality of mesh Access Points A to F, a plurality of stations STA1 to STAN, and an SIP server 2.
In comparison with the structure of the second embodiment shown in
Referring next to
Each of the Access Points A to F and the mesh portal 10 on the mesh network carry out operations similar to the control operation shown in
As a result, by setting any station (STA1 to STAN) having established a communication line for IP telephone communication with either one of the Access Points A to F or the portal 10 to the state of communicating data through virtual IP telephone communication, it is possible to set the wireless LAN mesh network NW to the maximum band state.
Subsequently, in the maximum band state of the mesh network, an additional station STA not having established a communication line for IP telephone communication sends, via the Access Point F to the SIP server 2, an association request (INVITE) for IP telephone communication with a destination station STA coupled with an external network (step S31).
After having received the association request (INVITE), the SIP server 2 transmits connection information between the connection source station STA and the destination station STA to the manager 1 (step S32).
When the connection information is received, the manager 1 identifies, using the information, the Access Point F linked with the source station STA and the portal 10 coupled with the destination station STA. The manager 1 delivers a control instruction to the Access Point F and the portal 10 to conduct trial IP telephone communication (step S33).
The Access Point F and the portal 10 receive the control indication and then carry out operation as in the second embodiment. Specifically, each thereof creates trial IP packet data including dummy data capable of identifying IP telephone communication on the mesh network NW. The Access Point F and the portal 10 mutually communicate the trial IP packet data via a relay network with each other to gather communication quality information such as delay, deviation, a packet loss required to evaluate quality of the IP telephone communication (step S34). Processing in steps 35 to 38 is similar to that of steps S25 to S28 of the second embodiment.
In the third embodiment, when a association request (INVITE) for IP telephone communication is received from an additional station STA to start IP telephone communication, the SIP server 2 controlling connection for IP telephone communication sends connection information between the additional station STA and a destination station STA to the mesh connection manager 1. When the connection information is received, the manager 1 identifies, according to the information, a mesh Access Point F and a mesh portal 10 coupled with the additional station STA and the destination station STA and then makes the mesh Access Point F and the mesh portal 10 execute trial IP telephone communication. Resultantly, as in the second embodiment, it is possible to determine, in the maximum band state of the mesh network, connectibility of the additional station STA for IP telephone communication. Therefore, even in a situation in which the stations (STA1 to STAN) having established communication lines for IP telephone communication on the wireless LAN mesh network NW include a station STAN in the silent state not communicating data through mesh Access Point F and a mesh portal 10, the communication system can determine connectibility for IP telephone communication with high reliability.
As can be seen from
In this connection, the embodiments above are only favorable embodiments of the present invention. The present invention is not restricted by the embodiments and the embodiments can be modified and changed in various ways within the scope and the spirit of the present invention.
For example, although the mesh connection manager 1 of the second and third embodiments is arranged on an external network, it is possible to dispose the manager 1 on the mesh network by use of, for example, an extended function of the mesh Access Points A to F. Also, the function of the manager 1 may be installed in the respective Access Points A to F.
The timing at which control devices such as the Access Points AP1 to APN of the first embodiment and the mesh Access Points A to F and the mesh portal 10 of the second and third embodiments conduct the control operation as shown in
In the embodiments of an IP telephone communication system, the judge criterion to determine whether a station has established a communication line for IP telephone communication does not restrict the present invention. The determination may be conducted according to a judge criterion prescribed in one of various system control operations. In short, any judge criterion may be available only if it is possible to manage stations having established communication lines for IP telephone communication.
Also, in the embodiments, the silent station STAN in the silent state is not limited to a station not communicating data through IP telephone communication due to use of, for example, a silent compression function. The silent station includes a station for which a band is secured for IP telephone communication in the IP telephone communication system and which is not conducting IP telephone communication.
The control operation of the control devices such as the Access Points AP1 to APN of the first embodiment and the mesh connection managing unit 1, the mesh Access Points A to F, and the mesh portal 10 of the second embodiment may be conducted by not only a hardware configuration but also by a software configuration including software such as a computer program. The program may be recorded in a recording medium, for example, an optical recording medium, a magnetic recording medium, a magnetooptical recording medium, or a semiconductor recording medium such that the program is read therefrom to be loaded in the control devices for the control operation. Also, the program may be loaded in the control devices via a predetermined network from an external device connected thereto so that the devices carry out the control operation.
The connection controller, the IP telephone communication system, the connection control method, and the connection control program in accordance with the present invention are applicable to IP telephone communication of multimedia data including audio data and video data as well as to a network environment including a station in the silent state not communicating data through IP telephone communication.
Number | Date | Country | Kind |
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2006-092221 | Mar 2006 | JP | national |