Patent Application
20170238162
The present invention relates to a wireless communication network including terminals that are capable of peer-to-peer (hereinafter, abbreviated as “P2P”) wireless connection to each other (P2P terminals), and a communication technique in the same.
In recent years, Wi-Fi Direct has attracted attention as a terminal-to-terminal communication scheme in view of broader bandwidth, increased security, and the like. While conventional Wi-Fi networks work in the infrastructural mode with a specific device serving as an access point (AP), Wi-Fi Direct-compliant networks enable communication to be performed within a group, with any P2P terminal, not a specific device, serving as a group owner (NPL 1). A group owner is a P2P terminal that operates as an access point of a group and, as the parent of that group, can form the group including other P2P terminals as clients.
Within a P2P group formed as described above, terminals can share data and transfer data at high speed without connecting to the Internet or the like. Wi-Fi Direct, in particular, supports a robust security protocol and therefore can realize a higher level of security than the conventional ad-hoc mode (IBSS: Independent Basic Service Set and the like).
According to the above-described Wi-Fi Direct, when a group is formed between terminals, each P2P terminal first performs Device Discovery processing for searching for a P2P terminal in vicinity by alternately repeating Search state and Listen state. That is, in Search state, a P2P terminal sends out a search request (Probe Request) while sequentially changing predetermined channels (channels #1, #6, #11) and waits for a response thereto (Probe Response). In Listen state, a P2P terminal waits for Probe Request from another terminal and, if receiving Probe Request, returns a response, Probe Response, thereto. In this search processing, each terminal switches Search state and Listen state at random intervals, and therefore connection processing can be initiated between terminals if one of the terminals can send out Probe Request in Search state and the other can return a response, Probe Response, to this search request in Listen state on the same channel.
However, client terminals in a P2P group mutually perform communication by using a single channel within this group. Accordingly, if search processing cannot be performed on other channels than this channel for use, the group owner has no way of knowing a terminal or group that is present in the vicinity of this group.
Moreover, if terminals in a group can perform search processing on other channels than the channel for use, communication within the group cannot be performed while they are performing such search processing, and consequently communication performance within the group is lowered. Further, in search processing, switching between channels and switching between Search state and Listen state are performed as described above, and accordingly frequent execution of search processing by a client terminal hastens its battery consumption.
Accordingly, an object of the present invention is to provide a method, a system, and a wireless terminal that can search for a neighboring terminal efficiently within a group.
A communication system according to the present invention is a communication system in a wireless communication network including a plurality of terminals that can form a peer-to-peer group, and is characterized in that an owner terminal operating as an access point in one group designates part of client terminals in this group as a searching terminal, and the searching terminal searches for a terminal that is present in vicinity.
A wireless terminal according to the present invention is a wireless terminal that can form a peer-to-peer group with another wireless terminal in a wireless communication network, and is characterized by including: in case of operating as an access point in a first group, a search designation means for performing search designation to cause one or a plurality of other wireless terminals in the first group to operate as a searching terminal. Further, in case of operating as a client in a second group, the wireless terminal can also include a search control means for performing operation of searching for a terminal that is present in vicinity when designated as a searching terminal by an owner terminal that operates as an access point in the second group.
A control method for a communication system according to the present invention is a control method for a communication system in a wireless communication network including a plurality of terminals that can form a peer-to-peer group, and is characterized by including: by an owner terminal that operates as an access point in one group, designating part of client terminals in this group as a searching terminal; and by the searching terminal, searching for a terminal that is present in vicinity.
A control method for a wireless terminal according to the present invention is a control method for a wireless terminal that can form a peer-to-peer group with another wireless terminal in a wireless communication network, and is characterized by including: by a control means, causing the wireless terminal to operate as an owner terminal that operates as an access point in one group; by a selection means, selecting one or a plurality of other wireless terminals within this group; and by a designation means, designating the selected other wireless terminal as a searching terminal.
A control method for a wireless terminal according to the present invention is a control method for a wireless terminal that can form a peer-to-peer group with another wireless terminal in a wireless communication network, and is characterized by including: by a control means, causing the wireless terminal to operate as a client terminal in one group; and by a search control means, performing operation of searching for a terminal that is present in vicinity when the wireless terminal is designated as a searching terminal by an owner terminal that operates as an access point in the group.
According to the present invention, a searching terminal is designated, whereby it is possible to search for a neighboring terminal more efficiently within a group.
According to exemplary embodiments of the present invention, one or a plurality of client terminals within a P2P group are designated, and the designated terminals are charged with a role for searching for other terminals. That is, the designated terminals search for terminals that are present in vicinity, and the other client terminals do not perform search operation. Not all client terminals but part of the client terminals are designated as searching terminals, whereby it is possible to suppress lowering of communication performance within a group, and to search for neighboring terminals more efficiently within the group. Further, terminals that perform search operation are limited, whereby it is possible to reduce power consumption in an entire group. Note that a designated searching terminal may disconnect from the group it belongs to and search channels (search all channels in the system or search a plurality of predetermined channels), or may search channels without disconnecting. Furthermore, a designated searching terminal may perform search operation not only when it is designated but also at designated time intervals or at predetermined period.
A searching terminal notifies information on another terminal it has discovered to the group owner, whereby the information on the other terminal can be shared within this group. If the searching terminal disconnects from the group it belongs to, the searching terminal reconnects to the original group and thereby can notify the information on the other terminal to the group owner.
Moreover, a searching terminal may be designated sequentially from among a plurality of client terminals that are selected beforehand. For example, a searching terminal is designated one by one from among the plurality of selected client terminals through a predetermined procedure taking fairness into account. Alternatively, the plurality of selected terminals are divided into two sub-groups, and a searching terminal may be designated in accordance with different time allocation and/or different procedures between the sub-groups. Hereinafter, the exemplary embodiments of the present invention will be described in more detail with reference to drawings.
According to a first exemplary embodiment of the present invention, an arbitrary or specified client terminal within a group is designated as a searching terminal, and only the designated searching terminal performs operation of searching for another terminal that is present in vicinity. The searching terminal notifies information on a discovered terminal to the group owner to which the searching terminal itself belongs.
Referring to
The terminal N12 as a searching terminal sends a search request on predetermined channels or all channels including channels other than an operating channel in the group G1 (Operation S102) and receives a response to this search request from another terminal, thereby discovering the presence of this other terminal. In search of all channels, it is possible to discover not only a terminal N14 that forms a group but also a terminal N15 that does not form any group. Only the searching terminal N12 performs this search operation, and the other client terminals N13 and N11 operate as ordinary clients without performing search of channels. In
The searching terminal N12 notifies information on the other terminals included in the received responses to the group owner terminal N10 (Operation S103). Thus, the group owner terminal N10 can acquire the information on the terminals or the group that is present in the vicinity of the group G1. Since the client terminals N11 and N13 other than the searching terminal N12 do not perform search operation, they can suppress battery consumption and also can perform communication within the group G1.
The terminals N10 to N15 shown in
Referring to
The user control section 202 has a P2P automatic connection function that manages predetermined procedures for P2P terminal search, P2P group formation, joining, disconnection, and the like, and controls the wireless communication section 201 on behalf of a communication application. Note that similar control can be also performed by using a communication application. The information storage section 203 stores a message shared within a group to which the own terminal is connected, a message acquired from a searching terminal, history information in case of functioning as a searching terminal, or the like, which will be described later.
The program storage section 204 stores communication applications, searching terminal control programs, and the like in addition to programs for functioning as a terminal, and the control section 205 executes these programs and applications, thereby controlling operation as a P2P terminal, operation as a group owner or client, and operation as a searching terminal. In case the terminal is a group owner, the control section 205 performs control as a group owner and also performs, through a predetermined procedure, selection of a searching terminal, transmission of a search instruction signal to the searching terminal, acquisition of information on another terminal from the searching terminal, and storage thereof. In case the terminal is a client terminal serving as a searching terminal, the control section 205 performs control as a searching terminal and sequentially performs search for another terminal, acquisition of information from the other terminal, notification of the acquired information to the group owner, and the like.
As described above, according to the first exemplary embodiment of the present invention, one or some of the client terminals within a group are designated as searching terminals, and only the searching terminal(s) perform operation of searching for other terminals that are present in vicinity, whereby it is possible to maintain communication within the group by the other client terminals, and thus to suppress lowering of communication performance in the entire group. Further, since terminals that perform search operation are limited, it is possible to reduce power consumption in the entire group. Furthermore, the searching terminals notify information on discovered neighboring terminals to the group owner terminal, whereby the group owner can acquire information on the terminals in the vicinity of the group via the searching terminals.
According to a second exemplary embodiment of the present invention, part of the client terminals in a group is designated as a searching terminal, whereby this searching terminal temporarily disconnects from the group and performs search operation, and thereafter reconnects and notifies information on another terminal discovered to the original group. A system architecture and the configuration of a terminal N according to the present exemplary embodiment are similar to those of the first exemplary embodiment shown in
Referring to
The user control section 202 of each designated searching terminal, under control of the control section 205, disconnects the own terminal from the group owner terminal N10 through a predetermined procedure, and the searching terminal performs search of all channels (Operation S302). When acquiring information on a neighboring terminal through search operation, the user control section 202 reconnects the own terminal to the group owner terminal N10 via the wireless communication section 201 (Operation S303). Subsequently, the control section 205 notifies the acquired neighboring terminal information to the group owner terminal N10 via the wireless communication section 201 (Operation S304).
Referring to
When thus receiving the probe response from the terminal that is present in vicinity, the searching terminal N12 sends a request for reconnection to the group G1 to the group owner terminal N10 (Operation S406) and, if receiving a connection permission response from the group owner terminal N10 (Operation S407), makes reconnection as a client of this group G1. When becoming a client of the group G1, the searching terminal N12 notifies the group owner terminal N10 of the neighboring terminal information acquired through the search (Operation S408). The neighboring terminal information may be notified to the group members by UDP broadcast or the like, or may be notified by connecting to each member via a socket.
As described above, according to the second exemplary embodiment of the present invention, a searching terminal temporarily disconnects from a group and performs search operation, and thereafter reconnects to the original group and notifies information on another terminal. The searching terminal disconnects from the group and performs search, whereby the advantages can be obtained that the searching terminal can perform search operation sufficiently without any restrictions as a client terminal, and that search-related control performed by the group owner terminal is lightened.
According to a third exemplary embodiment of the present invention, all or part of the client terminals within a group are sequentially designated as a searching terminal in a predetermined order, and only the searching terminal performs operation of searching for another terminal that is present in vicinity. As described above, a terminal that is performing search greatly consumes battery and cannot perform communication within the group during search. Accordingly, it is preferable that the order of designating a searching terminal be determined from the viewpoint of fairness, but it is also necessary to efficiently search the vicinity of the group with sufficient precision. Accordingly, in order to make it possible to ensure fairness and sufficiently search the vicinity, a round-robin scheme, a random scheme, or a designation scheme taking account of a terminal's surroundings, battery status, or the like, or a combination of any of these schemes can be used for a designation procedure in the present exemplary embodiment.
Referring to
The terminals N10 to N1m shown in
Referring to
The program storage section 204a stores programs for functioning as a terminal, searching terminal control programs for controlling operation as a P2P terminal, operation as a group owner or client, and operation as a searching terminal, and searching terminal designation scheduler programs for determining the order in which the terminal serving as a group owner designates a searching terminal.
The control section 205a for the terminal serving as a group owner performs control as a group owner and also executes a searching terminal designation scheduler, thus sequentially sending a search instruction signal to a client terminal, acquiring information on another terminal from the searching terminal, and storing it in accordance with the predetermined designation procedure. The control section 205a for a client serving as a searching terminal performs control as a searching terminal and also sequentially performs search for another terminal, acquisition of information from the other terminal, notification of the acquired information to the group owner, and the like. Hereinafter, operation of a group owner terminal and of a searching terminal will be described with reference to
Referring to
First, the group owner terminal N10 gives a searching terminal designation only to the client terminal N12 (Operation S501), and the terminal N12, in response thereto, starts searching channels as a searching terminal (Operation S502). If receiving a response to this search from another terminal, the terminal N12 notifies information on this other terminal to the group owner terminal N10 (Operation S503) and returns to the original client terminal from the searching terminal.
The group owner terminal N10 that has received the other terminal information from the terminal N12 designated for search, subsequently gives a searching terminal designation only to the client terminal N13 (Operation S504), and the terminal N13, in response thereto, starts searching channels as a searching terminal (Operation S505). If receiving a response to this search from another terminal, the terminal N13 notifies information on this other terminal to the group owner terminal N10 (Operation S506) and returns to the original client terminal from the searching terminal. With respect to the terminal N11 as well, searching terminal designation, search, and notification are sequentially performed similarly. Thereafter, the client terminals are sequentially designated as a searching terminal in the round-robin manner and perform similar operation.
Next, a description will be given of an example of a search sequence by a terminal designated as a searching terminal, with reference to
In the search sequence S700 by the terminal N12, first, the group owner terminal N10 designates the client terminal N12 as a searching terminal (Operation S701), and the terminal N12, in response thereto, performs a procedure for disconnecting from the group owner terminal N10 (Operation S702). The searching terminal N12 starts a timer on which a predetermined search time T is set (Operation S703) and performs search without returning to the group G1 until timeout occurs.
When timeout of the timer occurs (Operation S704), the searching terminal N12 reconnects to the group owner terminal N10 and returns to the original group G1 (Operation S705). The reconnected terminal N12 transfers information on another terminal discovered through the search to the group owner terminal N10 (Operation S706), and the group owner terminal N10 stores the other terminal information in the information storage section 203.
Timer setting as described above makes it possible to cause a searching terminal to perform search for a certain period of time and also certainly return to its original group. Note that the group owner terminal N10 can also perform control such that timer setting on a searching terminal is not made. Alternatively, it is also possible that the control section 205a of a searching terminal determines whether or not to set a return timer on its own station.
Moreover, the search operation of a searching terminal is managed by using a timer in the present exemplary embodiment, but also can be managed by additionally using the number of neighboring terminals to be discovered. For example, it is also possible that the number of neighboring terminals is designated, and a searching terminal returns after it has discovered the designated number of neighboring terminals or after the predetermined search time T has passed.
The group owner terminal N10 can use the above-described round-robin scheme for a way of designating a plurality of client terminals. However, various modes are conceivable for the order of designating a plurality of client terminals.
As illustrated in
As illustrated in
Moreover, if each client terminal has a location detection function and the group owner terminal N10 can acquire the location information of each client terminal, it is also possible that the group owner terminal N10 stores an area where a large number of terminals were discovered through past search as history information, and preferentially designates a client terminal that is in the same area or is close thereto as a searching terminal. Further, it is also possible that the clients are sequentially designated based on the distance from the group owner terminal N10, that is, starting from the most distant client from the group owner. Furthermore, it is also possible that the client terminals are sequentially designated as a searching terminal in the order of old connection to the group G1, or in the order of new connection to the group G1, by using a timestamp that indicates a time point when a client terminal joined.
As described above, the order of designating a searching terminal can be also determined based on throughput, battery charge remaining, the number of neighboring groups/neighboring terminals, distance from the group owner, or timestamp indicating a time point when a client terminal joined, or a combination of any of these items. Moreover, as the simplest method, any of all of the plurality client terminals may be selected at random as a searching terminal.
The group owner terminal N10 can be triggered to designate a searching terminal, for example, by a condition as listed below.
As described above, according to the third exemplary embodiment of the present invention, part of the plurality of client terminals within a group are sequentially designated as a searching terminal through a predetermined procedure, and only the designated searching terminal performs operation of searching for another terminal that is present in vicinity, whereby it is possible to secure battery consumption and fairness with respect to communication within the group. Moreover, the procedure of designating a searching terminal is determined based on information about each client terminal's status, surroundings, or the like, allowing more efficient search.
According to a fourth exemplary embodiment of the present invention, one or more client terminals are selected beforehand as specific terminals within a group, and the selected specific terminals are sequentially designated as a searching terminal. For example, a terminal that has an advantage in search operation such as having many neighboring terminals, or a terminal that has more than enough terminal performance such as throughput, battery capacity, or battery charge remaining is selected as a specific terminal. Thereby, it is possible to designate the selected specific terminals as main searching terminals, and thus to perform search scheduling taking account of fairness with the other terminals than the specific terminals.
Moreover, it is also possible that the clients within a group are divided into a plurality of sub-groups in accordance with a fixed criterion such as having an advantageous condition in search operation or having more than enough terminal performance such as throughput or battery charge remaining, and a searching terminal is designated in accordance with different time allocation and/or different designation procedures between the sub-groups. Hereinafter, the fourth exemplary embodiment will be described in detail by taking a case of two sub-groups, one consisting of specific terminals and the other consisting of other terminals, as an example.
Referring to
Further, according to the present exemplary embodiment, it is assumed that the plurality of client terminals are divided into a first sub-group consisting of the specific terminals N11 and N12 and a second sub-group consisting of the other client terminals N13 to N1m, and that a searching terminal is designated in the round-robin manner also in the second sub-group. However, time periods of search allocated to the first and second sub-groups are different.
A terminal N1s (s=1, . . . m) designated as a searching terminal performs operation of searching for another terminal that is present in vicinity and notifies information on a discovered terminal to the group owner terminal N10, as described above.
Referring to
Subsequently, the group owner terminal N10 allocates different search times T1 and T2 to the first sub-group consisting of the specific terminals and the second sub-group consisting of the other terminals than the specific terminals, respectively (Operation S903). The ratio between the search times T1 and T2 may be determined based on a condition or conditions such as the number of the specific terminals and battery charge remaining. For example, if the specific terminals in the first sub-group have leeway of battery charge remaining and the number of the specific terminals is larger than a predetermined number, then the search time T1 is set longer than T2, but if the number of the specific terminals is smaller than the predetermined number, then the search time T1 is set shorter than that in the case the number of the specific terminals is larger than the predetermined number, and the search time T2 is made longer relatively.
When allocating the search times T1 and T2, the group owner terminal N10 sequentially designates a searching terminal by repeating search designation in the first sub-group and search designation in the second sub-group according to the search times T1 and T2, respectively (Operation S904).
Note that search designation scheduling is not limited to the above-described example, but the order of designating a searching terminal described in the third exemplary embodiment and the like can be applied. Moreover, it is also possible to divide into three or more sub-groups and designate a searching terminal in accordance with different time allocation and/or different designation procedures among the sub-groups.
Referring to
As described above, according to the fourth exemplary embodiment of the present invention, in addition to the effects of the above-described first to third exemplary embodiments, it is possible to select as a specific terminal, for example, a terminal that has an advantage in search operation such as having many neighboring terminals, a terminal that has leeway of battery capacity or battery charge remaining, or the like, and to designate this specific terminal as a main searching terminal. Thereby, efficient search is possible, and search scheduling taking account of fairness with the other terminals than the specific terminal is also possible.
Next, a detailed description will be given of a case as an example of the present invention where the above-described systems according to the first to fourth exemplary embodiments of the present invention are applied to a Wi-Fi Direct-compliant P2P network. Since basic configurational components and functions are as described above, illustrated below is a case where such configurational components and functions are implemented based on Wi-Fi Direct.
Referring to
In the terminal according to the present example, the WFD automatic connection control section 1004 controls Wi-Fi Direct commands on behalf of an existing communication application. Accordingly, it is possible to automate the control according to Wi-Fi Direct, without modifying the existing application. For example, when wireless terminals come close to each other, they can automatically form a group and implement terminal-to-terminal communication within the group. Moreover, when a new terminal approaches an already established group, the terminal can automatically join the established group. Further, even if already established groups are in proximity to each other, the composition of each group is maintained without changing.
Referring to
In case of connecting to an existing GO (CASE 2), first, a terminal searches for a P2P terminal in its vicinity through Device Discovery processing, and if a discovered P2P terminal is a GO, the terminal connects to this GO through Provision Discovery processing. Subsequently, WPS Provision Phase-1 (authentication phase) and Phase-2 (encryption phase) are sequentially performed.
In case of connecting to a Persistent GO (CASE 3), first, a terminal searches for a P2P terminal in its vicinity through Device Discovery processing, and if a discovered P2P terminal is a Persistent GO, the terminal connects to this Persistent GO through Invitation processing. Subsequently, WPS Provision Phase-1 (authentication phase) and Phase-2 (encryption phase) are sequentially performed.
The Device Discovery operation is performed as illustrated in
The Device Discovery operation toward an existing GO is performed as illustrated in
The GO Negotiation operation in case of forming a group between terminals is performed as illustrated in
The Provision Discovery operation for connecting to an existing GO is performed as illustrated in
The Invitation operation for connecting to a Persistent-GO is performed as illustrated in
Referring to
Through the above-described Wi-Fi connection and disconnection flows, the above-described information sharing methods according to the first to fourth exemplary embodiments of the present invention can be implemented in a Wi-Fi P2P network.
The present invention can be implemented in a P2P network including a plurality of terminals (wireless terminals) that can dynamically form a group.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-164033 | Aug 2014 | JP | national |
This application is a National Stage Entry of International Application No. PCT/JP2015/004007, filed Aug. 10, 2015, which is based upon and claims the benefit of the priority of Japanese Patent Application No. 2014-164033. The entire contents of the above-referenced applications are expressly incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2015/004007 | 8/10/2015 | WO | 00 |
