JP2002026805A - Radio network and method establishing link - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish a link between radio terminals existing in the outside of an area, in which linking with radio base station is possible, with a mobile terminal as a repeater without investigating about the propriety of communication between all the terminals in a network. SOLUTION: When there is the radio terminal which cannot be linked with the radio base station, the radio terminal is searched with an optional radio terminal within the network as an agent. When this radio terminal is searched, the link is established between the radio base station and the radio terminal with the radio terminal having succeeded in the searching as a repeater.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless network in which a mobile unit is the center of a wireless terminal, and more particularly to a link establishment method for establishing a wireless link with a wireless terminal outside a linkable area with a wireless base station. .

[0002]

2. Description of the Related Art In a wireless network comprising a radio base station and a plurality of radio terminals, when a mobile terminal is provided, the radio wave coverage of the radio base station is limited, and the link with the radio terminal is caused by obstacles such as distances and walls. In many cases, wireless terminals cannot be established.

It is described that when a link must be established between such a wireless base station and a wireless terminal outside a linkable area, a terminal in a network relays the terminal between the base station and the terminal. Japanese Unexamined Patent Application Publication No. 8-2
There are known examples such as 74777.

[0004]

However, in the above-mentioned conventional example, a sequence for investigating whether or not each terminal in the network can communicate with each other before starting normal operation is required. Since the relay function is realized by referring to the mutual communication correlation table created by this sequence, there is a problem that it is not possible to cope with a case where the wireless terminal communicating with the wireless base station is a mobile body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to investigate whether communication between all terminals in a network is possible or not.
An object of the present invention is to provide a wireless network and a link establishment method capable of establishing a link between a wireless base station and a wireless terminal in an unlinkable area using a mobile terminal as a relay.

[0006]

In order to achieve the above object, a feature of the present invention is that a wireless terminal which cannot be linked to the wireless base station in a wireless network comprising a wireless base station and a plurality of wireless terminals. It is provided with a means for detecting, and a means for searching for a wireless terminal that cannot be linked, using any wireless terminal in the network as an agent when there is a wireless terminal that cannot be linked.

[0007] A feature of the invention according to claim 2 is that a link is established between the radio base station and the radio terminal using the radio terminal that has successfully searched for the radio terminal that cannot link as a relay.

A wireless base station according to a third aspect of the present invention divides a vacant time slot and uses the vacant time slot as a repeater for a wireless terminal that has successfully searched for the wireless terminal. A link is established between a base station and the searched wireless terminal.

A feature of the invention of claim 4 is that, when the searched wireless terminal is unregistered in the network, the wireless base station succeeds in the search with the searched wireless terminal. After establishing a link using the wireless terminal as a repeater, the registration information is sent from the searched wireless terminal, and the wireless terminal is registered in the network.

According to a fifth aspect of the present invention, in a wireless network including a wireless base station and a plurality of wireless terminals, a link establishing method for establishing a link between the wireless base station and a wireless terminal in an unlinkable area. Detecting a wireless terminal that cannot be linked to the wireless base station, and, if there is a wireless terminal that cannot be linked, searching for a wireless terminal that cannot be linked with any wireless terminal in a network as an agent; Establishing a link between the wireless base station and the wireless terminal using the wireless terminal that has been successfully searched as a repeater when a wireless terminal is searched.

According to the present invention, even in a wireless network centered on a mobile object, an unknown wireless terminal outside the radio wave arrival is searched for by using a wireless terminal in the network as an agent, and the wireless base station and the unknown wireless terminal are connected. A link is established between the wireless terminals that have become agents as repeaters. At this time, the vacant time slots are divided, and a link between the radio base station and the unknown radio terminal is established using these vacant time slots. This can be realized without interrupting the existing link or lowering the communication rate.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration according to an embodiment of the wireless network of the present invention.
There is a space (010) whose periphery is closed by a wall or the like, in which a wireless network centered on a wireless base station (030) is installed. All wireless terminals registered in the wireless base station (030) are mobile terminals, and the wireless terminal 1 (040),
There is a wireless terminal 2 (050) and a wireless terminal 3 (060).

The range of radio waves of the radio base station (030) in the closed space (010) is indicated by a broken line as the radio base station radio wave range (035). On the other hand, the wireless terminal 2 (05
0) to the radio wave coverage of the wireless terminal 2 (05).
5) is indicated by a dashed line. In the figure, the wireless terminal 3 (060) is within the radio wave range (055) of the wireless terminal 2.
Is present. In the example of FIG. 1, reflection of radio waves from a wall is not taken into consideration.

Next, the operation of this embodiment will be described.
In the example of FIG. 1, the wireless base station (030) is the wireless terminal 1
A link in a wireless section between (040) and the wireless terminal 2 (050) has been established. Since the obstacle wall (020) is present in the closed space (010) and the wireless terminal 3 (060) is not in the range of the wireless base station radio wave reach (035), the wireless base station (030) communicates with the wireless terminal 3 (060). ) Cannot be established, and whether or not it exists in the closed space (010),
It cannot be determined.

Therefore, in this embodiment, the radio base station (030)
Of a terminal that cannot establish a link because it is out of the radio base station radio range (035), the unknown terminal exists in the radio radio range of the terminal using the terminal that has already established the link as an agent. It employs a method that allows the user to search.

First, the radio base station (030) periodically checks the link status of all subordinate radio terminals for network management. Since the wireless terminal 3 (060) has moved to the shadow of the obstacle wall (020) as viewed from the wireless base station (030), it does not exist within the wireless base station radio wave range (035). Therefore, as a result of the link status check by the wireless base station (030), the disconnection of the link of the wireless terminal 3 (060) is detected.

When the disconnection of the wireless terminal 3 (060) is detected, the wireless base station (030) firstly activates the wireless terminal 1 (060).
(040) Order search for the wireless terminal 3 (060) as an agent of the wireless base station (030).

The wireless terminal 1 (040) is connected to the wireless terminal 3 (06).
If 0) cannot be found, the wireless base station (030) picks up the agent right from the wireless terminal 1 (040), and then orders the wireless terminal 2 (050) to search for the wireless terminal 3 (060).

When the wireless terminal 2 (050) detects a response from the wireless terminal 3 (060) as a result of searching the radio wave coverage (055) of the wireless terminal 2 as an agent, the wireless terminal 2 (050) opens an empty channel in the wireless network. Wireless terminal 3 (0
60) and the wireless base station (030), the wireless terminal 2 (050) relays.

At this time, the radio base station (0
30) does not affect the link between the wireless terminal 2 (050).

The principle of the link in the wireless section in the wireless network at this time will be described with reference to FIGS. FIG. 2 shows a state where the wireless base station and the wireless terminals A, B and C are normally linked. A frame operated by one carrier is time-divided into a total of eight time slots of four transmission channels and four reception channels.

Among them, T1 which is the first time slot of the transmission group and R1 which is the first time slot of the reception group are control channels, and time slots are allocated between the radio base station and each radio terminal. .

In FIG. 2, a radio terminal A has a time slot T
2, the data transmitted by the wireless base station is received, and the data is transmitted to the wireless base station through the time slot R2. Similarly, the wireless terminal B transmits time slots T3 and R3.
And the radio terminal C is linked to the radio base station using time slots T4 and R4.

FIG. 3 shows a state in which the wireless terminal C cannot directly link to the wireless base station based on the link state between the wireless base station and each wireless terminal described in FIG. In such a case, if the time slot T4 is not used, the time slot T4 is set to T4A and T4B, and the time slot R4
Into R4A and R4B, each of which is divided into two auxiliary time slots. Using the divided portion of the time slot, another wireless terminal searches for wireless terminal C as an agent at the command of the wireless base station, and wireless terminal B that has been found becomes a repeater, and wireless base station and wireless terminal C communicate with each other. Will be linked indirectly.

The radio base station transmits data to be transmitted to radio terminal C to radio terminal B through time slot T4A. The wireless terminal B transmits the data addressed to the wireless terminal C received through the time slot T4A to the wireless terminal C through the time slot R4B.

Data transmitted from the radio terminal C to the radio base station is transmitted to the radio terminal B through the time slot T4B. The wireless terminal B transmits data received through the time switch T4B to the wireless base station through the time slot R4A.

The above is the procedure in which the wireless terminal C indirectly establishes a link with the wireless base station and performs data communication using the wireless terminal B as a relay.

This method involves the risk that the original communication rate is reduced by half because the time slot is divided, but on the other hand, if the time slot in the frame is free, any wireless terminal can be used as a repeater. Can be used, and even if the wireless terminal serving as a repeater is communicating,
It can be said that it is optimal for mobile communication without affecting links already established.

Next, a specific example of this embodiment will be described below.

FIG. 4 is a diagram for explaining a specific operation for establishing a link with a wireless base station and a wireless terminal outside the linkable area (first embodiment). This example shows a wireless monitoring system using a wireless network installed indoors.

In the building (240), a LAN (110)
As a backbone network, wireless base station A (120),
A wireless base station B (130) and a wireless base station C (140) are connected.

These wireless base stations A, B, and C can establish links with up to three wireless terminals with one wireless base station by using the wireless interface having the frame structure described with reference to FIG. . The wireless terminal performs data communication with a computer (100) connected to a LAN (110), which is a backbone network, via a wireless base station.

In this embodiment, there are two types of wireless terminals linked to the wireless base station through the wireless interface. Part 1
The type is a fixed type wireless surveillance camera. On the first floor are wireless surveillance cameras D (210) and E (220). On the second floor, wireless surveillance cameras A (150) and B (170). , A wireless monitoring camera C (180) is installed.

Another type of wireless terminal is a mobile wireless monitoring camera for taking and recording of a nearby area when a patrol is carried by a security guard or the like. The mobile wireless monitoring camera F (23) is provided on the first floor.
0), there is a mobile wireless monitoring camera G (160) on the second floor,
There is a mobile wireless monitoring camera H (190) and a mobile wireless monitoring camera I (200).

In this embodiment, the mobile radio monitoring camera I (2
00) enters a space separated by a sill in the building (240), and the radio wave of the linked radio base station C (140) does not reach, and the link is disconnected. At this time, in the area of the wireless base station C (140), there are the wireless monitoring camera C (180) and the mobile wireless monitoring camera H (190), each of which has established a link. Slot is empty.

The computer (100) loses its link with the mobile radio surveillance camera I (200) established via the radio base station C (140) by a terminal check performed at regular intervals for network status monitoring. When the wireless base station C (180) detects that the
The time slots T4 and R4 are divided as shown in FIG. Next, the computer (100) operates the radio base station C (140).
Via the wireless monitoring camera C (18
For 0), an instruction to search whether or not there is a response from the mobile radio monitoring camera I (200) using the T4B and R4B time slots is given.

If the mobile surveillance camera I (200) cannot be found as a result of the search by the radio surveillance camera C (180), then the mobile radio surveillance camera that has already established a link with the radio base station C (140) H (190) is instructed to search whether or not there is a response from the mobile wireless monitoring camera I (200).

When the mobile radio surveillance camera H (190) obtains a response from the mobile radio surveillance camera I (200) that is within the radio wave range while sandwiching the threshold, the mobile radio surveillance camera H (190) The link between the own station and the mobile radio monitoring camera I (200) is established using the half channel of the time slot (T4B, R4B in FIG. 3), and then the remaining half channel (T4A, R4A in FIG. 3). ) Is used to establish a link between the radio base station C (140) and its own station.

Thus, the mobile radio monitoring camera I (200)
When the link of the wireless interface between the wireless base station C (140) and the wireless base station C (140) is established, the wireless base station C (140)
By establishing a link between the computer (100) and the mobile radio surveillance camera I (200) via the N (110), all wireless terminals in the building (240) and the computer (100) can be connected. Link is established.

FIG. 5 is a diagram for explaining a specific operation of establishing a link between a wireless base station and a wireless terminal located outside the linkable area (second embodiment). This example is an example applied to a home network.

The building (300) is a general detached house. In this, a wireless network to which the present invention is applied is constructed, and a main controller (310) which also serves as a data aggregation device and a wireless base station becomes a center and a building (30).
And 0) overall control of electrical appliances such as home appliances and AV equipment.

The wireless network expands the wireless communication area by improving the noise immunity by using the spread spectrum technology with the radio wave intensity conforming to the specified small power suitable for the narrow space such as indoors.

The main controller (310) always cooperates with the wireless multi remote controller (320) as a console for the user to make settings and display the status of each electric appliance.

The appliances controlled by the main controller (310) include a wireless air conditioner A (330), a wireless air conditioner B (340), a wireless VTR (350), a wireless refrigerator (360), and a wireless door phone. (380) and various lighting devices (390).

Also, a wireless audio set (370)
Has just been installed and is not registered in the main controller (310).

The main controller (310) includes a wireless air conditioner A (330) and a wireless air conditioner B (340).
For the wireless VTR (350), the reservation setting of video recording is performed, and for the wireless refrigerator (360), the setting of the refrigerator temperature is performed. , Perform video reception of the camera in the refrigerator, perform video reception of the visitor, transmit response voice, and automatically respond to the wireless door phone (380), and perform lighting control for various lighting devices (390). .

The main controller (310)
At the same time, monitoring the failure status of all the appliances under its control.

Although not shown in FIG. 5, a link is always required when monitoring the source of a fire such as a water heater. As described above, the communication between the main controller (310) and the subordinate appliances is performed as described above. Most of the content has low data volume, so intermittent links are fine.

For this reason, when the frames described with reference to FIGS. 2 and 3 are used in the present embodiment, only the appliances that require a link at all times occupy one of the time slots, and the remaining appliances are used. About the main controller (3
10), a link may be established with one appliance, and a necessary packet exchange may be completed to release the link and shift to communication with the next appliance.

Since the wireless multi-remote controller (320) is a mobile body, the link is interrupted when the radio remote controller (320) is out of the radio wave range of the main controller (310).

Whether or not one of the time slots of the frame in FIG. 2 is occupied or not, the wireless multi-remote controller (320) serving as an interface with the user as a console has the highest priority over other appliances. The main controller (310) needs to recover the communication state as much as possible even when the link is lost and cannot be re-established.

In this embodiment, a wireless multi remote controller (32
0) is an example in which the present invention is applied as one means for recovering the communication state with the main controller (310).

When the wireless multi remote controller (320) is moved out of the building (300), the radio remote controller (320) moves out of the radio wave range of the main controller (310).
If the request for establishing the link of the wireless section interface to 0) cannot be satisfied, first the main controller (310)
Divides time slots T4 and R4 as shown in FIG.

The main controller (310) issues a command to search for the wireless multi-remote controller (320) using the T4B and R4B time slots in order, using an electric appliance as a subordinate wireless terminal as an agent.

Upon receiving the search command, the appliance transmits a link request for establishing a wireless section interface from its own station to the wireless multi remote controller (320) using the R4B time slot.

FIG. 5 shows a wireless multi remote controller (320) in the vicinity of the wireless door phone (380), and shows that the wireless multi remote controller (320) is in the radio wave reach range of the wireless door phone (380). expressing.

When the wireless multi-remote controller (320) responds to the link establishment request of the wireless intercom (380), the wireless intercom (380) and the wireless multi-remote controller (32) respond.
0) are the time slots T4B and R4B
Established by

Subsequently, the wireless door phone (380) establishes a link with the main controller (310) using the remaining time slots T4A and R4A,
The wireless doorphone (380) serves as a repeater, and the main controller (310) and the wireless multi remote controller (32)
0) is established.

The wireless audio set (3) shown in FIG.
70) is just installed and the main controller (3
10) is not recognized as a terminal in the wireless network, so that services realized by other appliances cannot be received.

The main controller (310) is simultaneously searching for a new terminal in a normal traveling sequence. At this time, the wireless audio set (370) as a new wireless terminal is connected to the main controller (310).
If the radio wave is not within the radio wave coverage area, the search for a new wireless terminal is usually terminated.
If the user pushes the specific button of 10) or operates the wireless multi remote controller (320) to appeal the existence of the new wireless terminal, the main controller (310)
, As in the previous embodiments, sequentially instructs a search for electric appliances that are subordinate wireless terminals as an agent.

In FIG. 5, the wireless refrigerator (36) is located near the wireless audio set (370) outside the radio wave range of the main controller (310) in the shadow of the stairs.
0) is drawn to indicate that a wireless audio set (370), which is a new wireless terminal, is within the radio wave reach of the wireless refrigerator (360).

The wireless refrigerator (360) instructed by the main controller (310) to search for a new wireless terminal is:
Using the divided frame shown in FIG. 3, a link establishment request for a new wireless terminal is transmitted with a global ID to a new wireless terminal that does not have a terminal ID of a wireless terminal in a wireless network. Only the new wireless terminal responds to this link establishment request.

When the wireless audio set (370) establishes a link with the audio set by responding to the link establishment request of the new wireless terminal, the wireless refrigerator (360) continues. 360) establishes a link with the main controller (310), and establishes a link between the main controller (310) and the new wireless terminal, the wireless audio set (370), using the wireless refrigerator (360) as a repeater. Establish a link.

On this link, the main controller (3
10) Terminal I as a registration terminal in the wireless network
Automatically start D provision and complicated registration work.

With this automatic registration system, the user does not have to perform complicated registration work on the wireless network,
Just by installing, you can receive various services of wireless network.

In the same manner as in the present embodiment, in a wireless network including a wireless base station and a plurality of wireless terminals, an unregistered wireless terminal can be searched for and automatically registered. In addition, the present invention is not limited to the above-described embodiment, and does not depart from the gist thereof.
Specific configurations, functions, operations, and effects can be implemented in other various forms.

[0067]

As described above in detail, according to the present invention, a wireless terminal having an established link is searched for a wireless terminal outside the linkable area, so that all the terminals in the network can be searched. It is possible to establish a link between the wireless base station and the wireless terminal outside the linkable area by using the terminal that has succeeded in the search as a relay without investigating whether or not communication is possible.

Also, after establishing a link between the wireless base station and the wireless terminal outside the linkable area, if this terminal is an unregistered terminal, it is required to send registration information through the link. Thereby, the terminal can be automatically registered in the network.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration according to an embodiment of a wireless network of the present invention.

FIG. 2 is a diagram showing a normal link state between a wireless base station and a wireless terminal.

FIG. 3 is a diagram illustrating a state where a wireless base station and a wireless terminal cannot be directly linked;

FIG. 4 is a diagram of a first embodiment illustrating a specific operation of establishing a link between a wireless base station and a wireless terminal outside a linkable area;

FIG. 5 is a diagram of a second embodiment illustrating a specific operation of establishing a link between a wireless base station and a wireless terminal outside a linkable area;

[Explanation of symbols]

 010 Closed space 020 Obstacle wall 030 Wireless base station 035 Radio base station radio range 040 Radio terminal 1 050 Radio terminal 2 055 Radio range of radio terminal 2 060 Radio terminal 3

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference)

Claims (5)

[Claims] In a wireless network comprising a wireless base station and a plurality of wireless terminals, means for detecting a wireless terminal that cannot be linked to the wireless base station; and if there is a wireless terminal that cannot be linked, any wireless terminal in the network Means for searching for a wireless terminal that cannot be linked using the agent as an agent. 2. The wireless network according to claim 1, wherein a link is established between the wireless base station and the wireless terminal using, as a relay, a wireless terminal that has successfully searched for the wireless terminal that cannot be linked. . 3. The radio base station divides vacant time slots and uses these vacant time slots to:
The wireless network according to claim 2, wherein a link is established between the wireless base station and the searched wireless terminal using the wireless terminal that has successfully searched for the wireless terminal as a relay device. 4. If the searched wireless terminal is unregistered in the network, the wireless base station links with the searched wireless terminal using the wireless terminal that succeeds in the search as a repeater. 4. The wireless network according to claim 2, wherein after establishing the wireless network, registration information is sent from the searched wireless terminal, and the wireless terminal is registered in the network. 5. A link establishment method for establishing a link between a radio base station and a radio terminal in an unlinkable area in a radio network including a radio base station and a plurality of radio terminals, comprising: Detecting a wireless terminal that cannot be linked; if there is the wireless terminal that cannot be linked, searching for the wireless terminal that cannot be linked using any wireless terminal in the network as an agent; and searching for the wireless terminal that cannot be linked. Establishing a link between the wireless base station and the wireless terminal using the wireless terminal that has succeeded in the search as a relay device.