JP2021019250A - Radio communication unit and radio network system using the same - Google Patents

Abstract

To provide a radio communication unit that enables a plurality of radio communication units to perform radio cooperation with a simple structure and, then, enables easy implementation of cooperative operation among the plurality of units and more flexible setting of connection topology between radio communication units.SOLUTION: In one radio communication unit are provided a plurality of relay radio communication sections, each of which receives an inter-upstream unit radio bearer setting request issued by an EPC function section (upstream EPC function section) of an upstream unit and, in response to reception of the inter-upstream unit radio bearer setting request, individually constructs an inter-upstream unit radio bearer together with an upstream radio base station. Therefore, not only a configuration in which a plurality of radio communication units are arranged in a straight-chain shape but also unit arrangement in a shape in which a plurality of inter-downstream unit radio bearers are made to branch on the upstream side from the one radio communication unit can be adopted. Thereby, connection topology between radio communication units can be set more flexibly and even a wide communication area can be covered efficiently.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wireless communication unit for performing wireless network communication with a mobile terminal, can easily realize a cooperative operation between a plurality of units, and can be suitably used for covering a wide area. The present invention relates to a wireless communication unit and a wireless network system using the wireless communication unit.

For example, in a high-speed communication standard based on the 3GPP specifications (for example, in a wireless communication network of LTE (Long Term Evolution) or WiMAX (Worldwide Interoperability for Microwave Access), an EPC (Evolved Packet Core) accommodating a wireless communication access network is included in the area. The wireless base station to which the mobile terminal is connected receives control of sending and receiving IP packets via the EPC. On the other hand, with the spread of mobile terminals such as mobile phones, smartphones and tablet PCs, it is necessary to construct the wireless base station at sea. I would like to use mobile terminals even in areas where EPCs and wireless base stations are not maintained in terms of infrastructure (hereinafter referred to as "wireless non-developed areas"), such as areas where communication functions have been lost due to depopulated areas or disasters. Is increasing.

In order to meet such demands, for example, Patent Document 1 proposes a composite wireless communication unit in which a wireless base station and an EPC functional unit are integrated. By installing such a wireless communication unit in the above-mentioned wireless non-developed area, a small-scale communicable area is constructed by the wireless base station unit included in the unit, and the EPC function unit in the unit controls communication. In this way, wireless communication can be performed between a plurality of mobile terminals connected to the radio base station unit. However, the communication area that can be covered by one wireless communication unit is narrow, and the communication capacity is also limited. In this case, it is conceivable to arrange multiple wireless communication units in a wireless non-maintenance area, but communication cooperation between the units is not considered, and communication between mobile terminals connected to different composite devices is not possible. There is a drawback that. In addition, when the number of mobile terminals connected increases or when a large amount of data such as video data is transmitted / received, or when the communication traffic in the area becomes excessive, there is a problem that problems such as congestion are likely to occur.

Therefore, Patent Documents 2 to 7 disclose a configuration in which a plurality of wireless communication units are linked and communication traffic from a mobile terminal is distributed and transferred to each wireless communication unit. Specifically, FIG. 6 of Patent Document 5 discloses a form via a satellite device as a cooperation path between wireless communication units for offloading communication with a mobile terminal.

JP-A-2016-12841 Japanese Unexamined Patent Publication No. 2018-137661 JP-A-2018-137662 JP-A-2018-137663 Japanese Unexamined Patent Publication No. 2018-137664 JP-A-2018-137665 JP-A-2018-137666

Patent Documents 2 to 7 show how a plurality of wireless communication units are interconnected (for example, FIG. 1 of Patent Document 2 and the like). Except for the off-road mode via the satellite device described above, no specific disclosure has been made in the literature as to what kind of entity this connection is composed of. However, if it is considered that the wireless communication units are connected by wire, if the wireless communication units are distributed and arranged in a relatively wide communication area in the wireless non-developed area, the communication cable connecting the devices will be used. It will be very long. As a result, the signal quality and communication capacity are deteriorated, and a relay device is required to prevent this, and there is a problem that the cost for constructing the connection infrastructure rises. Further, in applications such as trains, automobiles, and ships in which wireless communication units are mounted on a mobile body, it is physically impossible to connect the wireless communication units with cables. Further, if it is considered that the wireless communication units are also wirelessly connected to each other, no consideration is given to the connection topology of the wireless communication units in covering a wide communication area with the plurality of wireless communication units.

The object of the present invention is that a plurality of wireless communication units can be wirelessly linked by a simple structure, and thus a cooperative operation between the plurality of units can be easily realized, and the connection topology between the wireless communication units can be made more flexible. An object of the present invention is to provide a configurable wireless communication unit and a wireless network system using the same.

In order to solve the above problems, the wireless communication unit of the present invention is configured to be mounted on a mobile body, and is a wireless communication unit for performing wireless network communication with a mobile terminal. A wireless base station unit that can be connected via a wireless bearer for terminals, an EPC (Evolved Packet Core) function unit that is wiredly connected to the wireless base station unit and functions as a higher-level network control unit for the wireless base station unit, and a wired connection to the EPC function unit. As well as being connected, via the radio base station section of the upstream unit (hereinafter referred to as the upstream radio base station section) and the inter-unit radio bearer on the upstream side (hereinafter referred to as the upstream unit radio bearer), which is another wireless communication unit of the first. The radio base station unit is provided with a plurality of relay radio communication units that can be connected to each other, and the radio base station unit is the relay radio communication unit (hereinafter referred to as the downstream relay radio communication unit) of the downstream unit, which is another second radio communication unit, and the downstream side. It is possible to connect via a unit-to-unit radio bearer (hereinafter referred to as a downstream unit radio bearer), and the EPC function unit transmits a downstream unit radio bearer setting request to the radio base station unit, while the radio base station unit transmits the downstream unit radio. In response to the bearer setting request, a wireless bearer between downstream units is constructed together with the downstream relay wireless communication unit. The EPC function unit transmits the terminal wireless bearer setting request to the wireless base station unit, while the wireless base station unit wirelessly for the terminal. A wireless bearer for a terminal is constructed together with a mobile terminal in response to a bearer setting request, and the plurality of relay wireless communication units are wireless between upstream units issued by the EPC function unit of the upstream unit (hereinafter referred to as the upstream EPC function unit). It is characterized in that the bearer setting request is received, and the upstream unit radio bearer is individually constructed together with the upstream radio base station unit in response to the upstream unit radio bearer setting request.

Further, the wireless network system of the present invention is a wireless communication unit that is configured to be mounted on a mobile body and for performing wireless network communication with a mobile terminal, and the mobile terminal is via a wireless bearer for the terminal. A wireless base station unit that can be connected, an EPC (Evolved Packet Core) functional unit that is wiredly connected to the wireless base station unit and functions as a higher-level network control unit for the wireless base station unit, and an EPC functional unit are wiredly connected, and the first Multiple relays that can be connected via the wireless base station section of the upstream unit (hereinafter referred to as the upstream wireless base station section), which is another wireless communication unit, and the wireless bearer between units on the upstream side (hereinafter referred to as the wireless bearer between upstream units). A wireless communication unit is provided, and the wireless base station unit is a relay wireless communication unit (hereinafter referred to as a downstream relay wireless communication unit) of a downstream unit which is another second wireless communication unit, and a wireless bearer between units on the downstream side (hereinafter referred to as a wireless bearer). It is possible to connect via the downstream unit wireless bearer), and the EPC function unit transmits the downstream unit wireless bearer setting request to the wireless base station unit, while the wireless base station unit receives the downstream unit wireless bearer setting request downstream. A wireless bearer between downstream units is constructed together with the relay wireless communication unit. The EPC function unit transmits a terminal wireless bearer setting request to the wireless base station unit, while the wireless base station unit moves in response to the terminal wireless bearer setting request. A wireless bearer for terminals is constructed together with a terminal, and a plurality of relay wireless communication units receive an upstream unit wireless bearer setting request issued by an upstream unit EPC function unit (hereinafter referred to as an upstream EPC function unit). The radio consists of a group of radio communication units in which a plurality of radio communication units individually configured to individually construct an upstream unit radio bearer together with the upstream radio base station unit in response to the upstream unit radio bearer setting request are arranged. The communication unit group is connected by an inter-unit wireless bearer in a positional relationship in which base station cells of a pair of wireless communication units adjacent to each other partially overlap, and is also connected to a mobile terminal connected to one of the pair of wireless communication units and the other. The mobile terminal is characterized in that it transmits / receives an IP packet via a wireless communication unit pair and an inter-unit wireless bearer connecting the wireless communication unit pair.

In the wireless communication unit (and wireless network system) of the present invention, the plurality of relay wireless communication units can be configured such that an upstream unit-to-unit wireless bearer can be individually constructed between different upstream radio base station units. In this case, it is possible to individually construct an upstream unit radio bearer between a plurality of relay radio communication units and different upstream radio base station units using different frequency channels.

In the subordinate concept of the wireless communication unit (and wireless network system) of the present invention, when a plurality of relay wireless communication units detect a candidate for an upstream unit to be a new connection destination in a state where the upstream unit is disconnected. By transmitting an attach request for constructing an inter-upstream unit radio bearer to the radio base station unit of the candidate upstream unit, a request for setting an inter-upstream unit radio bearer is received from the candidate upstream unit and between the upstream units. It can be configured to include an inter-upstream wireless bearer construction control unit that controls the construction of a wireless bearer.

Further, the radio base station unit can be configured so that the relay radio communication units of the plurality of downstream units can be simultaneously connected to each other via the individual downstream unit radio bearers. In this case, the individual downstream unit radio bearers constructed between the radio base station unit and the relay radio communication unit of the plurality of downstream units can be constructed using the same frequency channel. Further, when the radio base station unit receives an attach request from a candidate for a newly connected downstream unit in a state where the number of connected downstream units is 1 or less, the radio base station unit notifies the EPC function unit of the attach request and also notifies the EPC function unit. It can be configured to include a downstream unit-to-unit wireless bearer construction control unit that receives a terminal wireless bearer setting request from the EPC function unit and controls to construct a downstream inter-unit wireless bearer with a candidate of the downstream unit. ..

On the other hand, the wireless communication unit of the present invention may be configured such that a plurality of wireless base station units are connected to one EPC control unit, and the relay wireless communication unit of each downstream unit can be connected. In this case, the relay radio communication units of the downstream units can be configured to be connected to the radio base station units connected to one EPC control unit by a wireless bearer between downstream units set on different frequency channels. ..

When the relay wireless communication unit is a wireless communication unit different from the upstream unit and there is a switching candidate unit capable of wireless connection with higher quality than the upstream unit, the relay wireless communication unit is connected to the switching candidate unit as a new upstream unit. It can be configured to have an upstream unit connection switching control unit for switching.

Further, the upstream unit connection switching control unit can be configured to switch the connection to the switching candidate unit as the connection with the upstream unit is disconnected due to the deterioration of the communication quality with the upstream unit.

The EPC function unit is provided with a downstream unit radio bearer forced disconnection instruction unit that instructs the radio base station unit to temporarily and forcibly disconnect the downstream unit radio bearer from the downstream unit, while the radio base station unit is provided. The downstream unit wireless bearer disconnection control unit that controls the disconnection of the downstream unit wireless bearer in response to an instruction is provided, and the upstream unit connection switching control unit is provided with the upstream unit wireless bearer disconnection as the upstream unit wireless bearer is disconnected. Communication quality is evaluated for each of the old upstream unit, which is a wireless communication unit that was connected as an upstream unit by the bearer, and the switching candidate unit, and wireless communication that should be connected as a new upstream unit based on the result of the communication quality evaluation. It can be configured to determine the unit. In this case, more specifically, the upstream unit connection switching control unit receives a CQI (Channel Quality Indicator) reference signal from each wireless communication unit, generates CQI information using the CQI reference signal, and generates CQI information of the CQI information. It can be configured to perform communication quality evaluation based on the content. Further, in the EPC function unit, when the number of connections of the downstream unit to the wireless communication unit to which the EPC function unit belongs reaches a predetermined upper limit, the wireless bearer forced disconnection instruction unit between the downstream units is operated between the downstream units. While instructing the wireless bearer to be temporarily and forcibly disconnected, if the number of connected downstream units is less than the upper limit, it can be configured to allow additional connections of downstream units.

In addition, the downstream unit wireless bearer forced disconnection instruction unit is a switching candidate that reflects the distance between the downstream unit distance information acquisition unit that acquires the downstream unit distance information that reflects the distance to the connected downstream unit and the switching candidate unit. The distance d1 between the switching candidate unit distance information acquisition unit that acquires the unit distance information and the switching candidate unit that is reflected in the acquired switching candidate unit distance information is the downstream unit that is reflected in the acquired downstream unit distance information. It can be configured to give an instruction to temporarily and forcibly disconnect the wireless bearer between downstream units when the distance becomes smaller than the distance dc.

A current position acquisition unit for acquiring the current position of the wireless communication unit is provided, and the downstream unit distance information acquisition unit and the switching candidate unit distance information acquisition unit acquire their current positions from the downstream unit and the switching candidate unit, and their current positions are acquired. It can be configured to calculate the distance to the front-downstream unit and the distance to the switching candidate unit based on the information of the current position. Further, the downstream unit-to-unit radio bearer forced disconnection instruction unit may be configured to periodically output an instruction to disconnect the downstream unit-to-unit radio bearer at predetermined time intervals.

Further, the EPC function unit connects the relay radio communication unit of a plurality of mobile terminals and other radio communication units connected to the radio base station via the radio bearer for terminals within the communication area of the radio base station unit. It is equipped with a connected terminal registration unit that registers the terminal specific information of the mobile terminal inside, and collates the mobile terminal that is the destination of the IP packet transferred from the wireless base station unit with the registered contents of the connected terminal registration unit and transmits it. When the destination mobile terminal indicates a mobile terminal corresponding to any of the terminal specific information registered in the connected terminal registration unit, the IP packet is transferred back to the mobile terminal at the wireless base station unit. On the other hand, when the mobile terminal to be the transmission destination indicates a mobile terminal that is not registered in the connected terminal registration unit, the IP packet is sent from at least one of the relay wireless communication unit and the wireless base station unit to the transmission destination outside the wireless communication unit. It can be configured to control the transfer.

In this case, the EPC function unit creates an IP packet transfer table based on the shared terminal identification information of the relay wireless communication unit, refers to the transfer table to perform IP packet transfer control, and wireless network. When at least one of the number of wireless communication units included in the system and the connection order is changed, the system may be configured to have a transfer table update control unit that updates the contents of the transfer table according to the change. it can.

In the wireless network system of the present invention, in at least one of the wireless communication units, a plurality of relay wireless communication units can be configured to be connected to the wireless base station units of upstream units different from each other by an inter-unit wireless bearer. .. If the radio base station unit of the radio communication unit is configured so that the relay radio communication unit of a plurality of downstream units can be simultaneously connected via individual downstream unit radio bearers, at least the radio communication unit In one, a plurality of downstream units different from each other may be connected to the radio base station portion by an inter-unit radio bearer. In this case, the plurality of wireless communication units can be connected in a mesh pattern by an inter-unit wireless bearer.

Each EPC functional unit of a plurality of wireless communication units connected by an inter-unit wireless bearer is connected to the wireless base station via a terminal wireless bearer within the communication area of the wireless base station unit, and a plurality of mobile terminals and others. The relay wireless communication unit of the wireless communication unit of the above is equipped with a connected terminal registration unit that registers the terminal specific information of the mobile terminal connected to the wireless communication unit, and is a mobile terminal to which the IP packet transferred from the wireless base station unit is transmitted. When the mobile terminal to be the destination indicates a mobile terminal corresponding to any of the terminal specific information registered in the connected terminal registration unit by collating with the registered contents of the connected terminal registration unit, the IP packet is sent. While transferring to the mobile terminal in the form of being folded back by the wireless base station unit, when the mobile terminal to be transmitted indicates a mobile terminal that is not registered in the connected terminal registration unit, the IP packet is relayed to the wireless communication unit and the wireless base station unit. It can be configured to control transfer from at least one of the above to a destination outside the wireless communication unit.

In this case, the EPC function unit creates an IP packet transfer table based on the shared terminal identification information of the relay wireless communication unit, refers to the transfer table to perform IP packet transfer control, and wireless network. When at least one of the number of wireless communication units included in the system and the connection order is changed, it can be configured to have a transfer table update control unit that updates the contents of the transfer table according to the change contents.

In addition, the forwarding table is a connecting terminal registration unit in which the addresses of connected mobile terminals are registered in a list in each wireless communication unit, and a wireless communication unit that is the final transfer destination of received packets. The EPC function unit includes at least the number of wireless communication units and the connection order, which includes a routing table in which the address of is stored in association with the address of the wireless communication unit to be the next transfer destination of the received packet. When any of the changes is made, it can be configured to include a routing table changing unit that changes the contents of the routing table according to the changed contents. In this case, the wireless communication unit that is the final transfer destination of the packet is the destination node, and a plurality of wireless communication units that reach the destination node are the relay nodes, and the next transfer destination when the packet is transmitted to the destination node. With the wireless communication unit as the next hopping node, each wireless communication unit updates and sets the address of the next hopping node corresponding to the destination node in the routing table so that the route is optimized in the direction in which the number of relay nodes decreases. It can be configured as having a table update unit.

In the wireless communication unit of the present invention and the wireless network system using the same, relay wireless communication that can be connected to another wireless communication unit on the upstream side, the upstream unit (upstream wireless base station), via the wireless bearer between the upstream units. A part is provided. Further, the wireless base station unit can be connected to the downstream unit (downstream relay wireless communication unit), which is another wireless communication unit on the downstream side, via the wireless bearer between the downstream units. As a result, a plurality of wireless communication units can be connected by a wireless bearer between units, and a wireless network system covering a wider area can be easily constructed by the plurality of wireless communication units. Further, in the present invention, a plurality of relay wireless communication units are provided in one wireless communication unit, and the relay wireless communication units are issued by the EPC function unit (upstream EPC function unit) of the upstream unit to request the wireless bearer setting between upstream units. Is received, and the upstream unit radio bearer is individually constructed together with the upstream radio base station unit in response to the upstream unit radio bearer setting request. Therefore, the configuration is not limited to the configuration in which a plurality of wireless communication units are arranged linearly. It is also possible to adopt a unit arrangement in which a plurality of wireless bearers between downstream units are branched from one wireless communication unit to the upstream side. As a result, the connection topology between the wireless communication units can be set more flexibly, and it is possible to efficiently cover a wide communication area.

The schematic diagram which shows the concept of the wireless communication unit pair which becomes the structural unit of the wireless network system of this invention. The block diagram which shows the outline of the electrical structure of the wireless communication unit pair of FIG. The block diagram which shows an example of the electric structure of the wireless communication unit of this invention. The block diagram which shows an example of the electric structure of a UE (mobile terminal). Conceptual diagram of IP packet. The figure which conceptually shows the protocol stack of the control plane of 3GPP. The figure which conceptually shows the protocol stack of the user plane of 3GPP. The figure which conceptually shows the channel mapping of the downlink of 3GPP. Similarly, a diagram conceptually showing uplink channel mapping. The conceptual diagram which shows the relationship between a frequency band channel and a resource block. The figure which shows typically an example of the structural form of the wireless network system of this invention. Conceptual diagram of the channel map. A flowchart showing a flow of channel setting processing for a UE. A communication flow diagram showing an attachment sequence of a relay wireless communication unit of a wireless communication unit to another wireless communication unit on the upstream side. A communication flow diagram showing an attachment sequence to a wireless communication unit of a UE (mobile terminal). Conceptual diagram of the transfer table. A flowchart showing the flow of content update processing of the connected node registration unit due to the change of the adjacent node. A flowchart showing the flow of updating the contents of the routing table. A communication flow diagram showing an IP packet transfer control sequence between UEs connected to the same wireless communication unit. A communication flow diagram showing an IP packet transfer control sequence between UEs connected to adjacent wireless communication units. A communication flow diagram showing an IP packet transfer control sequence between UEs connected to both ends of three linearly connected wireless communication units. The communication flow diagram which shows the control sequence of a simple handover process. The figure explaining the first example of the process of attaching and connecting a new wireless communication unit to a wireless communication network system. The figure which also explains the 2nd example. Similarly, the figure explaining the third example. The figure explaining the reconnection process when the intermediate wireless communication unit disconnects in a wireless communication network system. The figure explaining the process of temporarily disconnecting a wireless bearer between units according to the distance between units, and incorporating the approaching wireless communication unit into the network in the form of being newly attached. Explanatory drawing following FIG. 27. Explanatory drawing following FIG. 28. The schematic diagram which shows the construction example of the wireless communication system which connected a plurality of wireless communication units in a network by the wireless bearer between units. Explanatory drawing which shows the concept of the shortest path when there are a plurality of routes from a source node to a destination node. The figure which shows an example of the CQI table. A flowchart showing a flow of processing for temporarily disconnecting an inter-unit wireless bearer according to an inter-unit distance. The flowchart which shows the flow of the connection adjustment process which determines the final connection destination based on CQI when a plurality of wireless communication units compete with each other as a new connection destination candidate due to disconnection of a radio bearer between units. Conceptual diagram of dynamic routing The figure which shows an example of the wireless network system configured by using the wireless communication unit which includes a plurality of wireless base stations.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic diagram showing the concept of a pair of wireless communication units, which is a constituent unit of the wireless network system of the present invention, as an embodiment. The wireless communication unit pair has wireless communication units 1 (A) and 1 (B) having the same configuration according to the embodiment of the present invention (hereinafter, also referred to as wireless communication unit pair 1 (A) and 1 (B)). , Each wirelessly communicates with the UE (mobile terminal) 5 according to the communication protocol stack of the method specified by 3GPP (in this embodiment, LTE is used, but other methods such as WiMAX may be used). It is configured as a thing.

The wireless communication units 1 (A) and 1 (B) are installed on the large vessels WS (A) and WS (B), which are mobile bodies, respectively, and are wirelessly connected by the inter-unit wireless bearer 55 described in detail later. The wireless communication units 1 (A) and 1 (B) form cells 50 (A) and 50 (B) to which the UE (mobile terminal) 5 can be connected, respectively. In addition, small vessels FB (eg, fishing boats, tugboats, etc.) are operating around the large vessels WS (A), WA (B) (for example, fishing motherships, tankers, etc.), and cell 50 (A) or cell 50. The crew of the small vessel FB in (B) is carrying the UE 5. The UEs 5 are wirelessly connected to the nearest wireless communication units 1 (A) and 1 (B) by a terminal wireless bearer 57, respectively. The UE 5 may be carried by the crew of the large vessels WS (A) and WA (B). Further, the installation destinations of the wireless communication units 1 (A) and 1 (B) may be a moving body (vehicle or the like) other than a ship, or may be fixedly arranged at a desired installation destination on land, for example.

FIG. 2 shows the functional block configuration of the wireless communication units 1 (A) and 1 (B). The wireless communication units 1 (A) and 1 (B) both have the same electrical configuration. When a plurality of wireless communication units and their components are distinguished from each other in the present specification, the same number is assigned to the corresponding component, and a capitalized alphabet in parentheses is assigned following the number. Shown. On the other hand, when each component is shown without distinguishing between wireless communication units, the uppercase alphabet in parentheses may be omitted. Hereinafter, the reference numerals on the wireless communication unit 1 (A) side will be mainly used, but the wireless communication unit 1 (B) side will also be described as necessary with reference to the corresponding reference numerals.

The wireless communication unit 1 (A) includes a wireless base station unit 4 (A) (eNodeB (evolved NodeB)) to which the UE (mobile terminal) 5 can be connected via the terminal wireless bearer 57, and a wireless base station unit 4 (A). It has an EPC (Evolved Packet Core) function unit 3 (A) that is wiredly connected to the radio base station unit 4 (A) and functions as an upper network control unit for the radio base station unit 4 (A). Further, the EPC function unit 3 (A) has an inter-unit radio bearer on the upstream side with respect to the radio base station unit 4 (B) (upstream radio base station unit) of the wireless communication unit 1 (B) (upstream unit) on the upstream side. A plurality of relay wireless communication units 9 (A1) and 9 (A2) that can be connected via (upstream unit wireless bearer) are connected by wire (two in this embodiment, but three or more can be used). There is. On the other hand, the wireless communication unit 1 (B) is wiredly connected to the same wireless base station unit 4 (B) and the wireless base station unit 4 (B), and functions as an upper network control unit for the wireless base station unit 4 (B). A plurality of relay wireless communication units 9 (B1) and 9 (B2) connected to the EPC function unit 3 (B) and the EPC function unit 3 (B) by wire (two in the present embodiment, but three or more). It can also be).

In both the wireless communication unit 1 (A) and the wireless communication unit 1 (B), the plurality of relay wireless communication units 9 (A1) and 9 (A2) and the plurality of relay wireless communication units 9 (B1) and 9 (B2) ) Can be independently connected to the wireless base station portion of the wireless communication unit via the inter-unit wireless bearer if another wireless communication unit is arranged on the upstream side. Further, in both the wireless communication unit 1 (A) and the wireless communication unit 1 (B), the wireless base station units 4 (A) and 4 (B) have the downstream wireless communication unit (downstream relay wireless communication unit). It is possible to connect a plurality of units (two in the present embodiment, but three or more) at the same time via a wireless bearer between units on the downstream side (radio bearer between downstream units).

In FIG. 2, the wireless communication unit 1 (A) is located on the downstream side of the wireless communication unit 1 (B), and the relay wireless communication unit 9 (A2) of the wireless communication unit 1 (A) is a unit-to-unit wireless bearer 55 ( It is connected to the wireless base station unit 4 (B) of the wireless communication unit 1 (B) by A). The wireless communication unit 1 (A) forms a downstream unit when viewed from the wireless communication unit 1 (B), the inter-unit radio bearer 55 (A) corresponds to the downstream inter-unit bearer, and the radio base station unit 4 (A) is the downstream radio. Corresponds to the base station section. In the opposite view, the wireless communication unit 1 (B) is located upstream of the wireless communication unit 1 (A), and the wireless base station section 4 (B) of the wireless communication unit 1 (B) is the inter-unit wireless bearer 55 (A). ) Is connected to the relay wireless communication unit 9 (A2) of the wireless communication unit 1 (A). When viewed from the wireless communication unit 1 (A), the wireless communication unit 1 (B) forms an upstream unit, the inter-unit wireless bearer 55 (A) corresponds to an upstream inter-unit bearer, and the radio base station unit 4 (B) is an upstream radio. Corresponds to the base station section.

Further, the wireless communication unit 1 (A) and the wireless communication unit 1 (B) are also connected to the wireless communication unit 1 (C) having the same electrical configuration. Specifically, in the wireless communication unit 1 (C), the relay wireless communication unit 9 (C1) is connected to the wireless base station unit 4 (A) of the wireless communication unit 1 (A) via the inter-unit bearer 55 (B1). The relay radio communication unit 9 (C2) is independently connected to the radio base station unit 4 (B) of the radio communication unit 1 (B) via the inter-unit bearer 55 (B2). The radio communication unit 1 (C) also includes a radio base station unit 4 (C) and an EPC function unit 3 (C). From the viewpoint of the wireless communication unit 1 (C), the wireless communication unit 1 (A) and the wireless communication unit 1 (B) both correspond to upstream units, and the inter-unit bearers 55 (B1) and (B2) are between upstream units. Corresponds to bearer. The inter-unit wireless bearers 55 (A), 55 (B1), and 55 (B2) are constructed according to the wireless protocol stack of the same method as the terminal-side wireless bearer 57, and in the present embodiment, all of them are constructed according to the LTE wireless protocol stack. To.

As described above, the plurality of relay radio communication units can individually construct an inter-upstream unit radio bearer between different upstream radio base station units. Further, in the radio base station section, relay radio communication sections of a plurality of downstream units can be simultaneously connected via individual downstream unit radio bearers. As a result, the connection topology between the wireless communication units can be set more flexibly, and it is possible to efficiently cover a wide communication area. Further, regardless of whether the wireless communication unit is on the upstream side or the downstream side, the plurality of other wireless communication units and the three wireless communication units 1 (A), 1 (B), and 1 (C) are three unit-to-unit wireless bearers. 55 (A), 55 (B1), 55 (B2) form a "mesh" of the network. For example, in a wireless network system including more wireless communication units, the two relay wireless communication units of each wireless communication unit are connected (attached) to the wireless base station units of different wireless communication units, as shown in FIG. A plurality of wireless communication units 1 are connected in a mesh pattern by an inter-unit wireless bearer 55 (the arrow indicates the direction of attachment, the starting point of the arrow corresponds to the relay wireless communication section, and the ending point of the arrow corresponds to the wireless base station section). It is possible to build a network system.

Next, in any of the wireless communication units 1 (A), 1 (B), 1 (C) (hereinafter, collectively referred to as wireless communication unit 1), the EPC function unit 3 is a gateway on the control plane side. MME (Mobility Management Entity) 2, S-GW (Serving Gateway) 6 as a gateway on the user plane side, EPC function unit 3, and upstream network element of the EPC function unit 3 (here, router 8 (described later)). It also has a P-GW (PDN (Packet Data Network) Gateway) 7 that is located at the node of the relay wireless communication unit 9) and manages the IP address toward the upstream network element side (that is, the upstream unit side). Further, a plurality of UEs 5 are wirelessly connected to the wireless base station unit 4 via the terminal wireless bearer 57. On the control plane side, the radio base station unit (eNodeB) 4 is connected to the MME 2 via the S1-MME interface. Further, on the user plane side, the radio base station unit 4 is connected to the S-GW 6 via the S1-U interface. Further, the S-GW 6 is connected to the P-GW 7 via the S5 interface. On the other hand, in a general LTE network, a plurality of radio base stations are connected to a common core network, and when the UE moves between cells of adjacent radio base stations, the radio base stations are connected to each other on the control plane side. Handover control is performed via the X2 interface or the S1 interface on the core network side. However, in the present embodiment, for example, when the UE moves between the cells 50 (A) and 50 (B) of the wireless communication units 1 (A) and 1 (B), both wireless communication units 1 (A) and 1 The radio base station units 4 (A) and 4 (B) of (B) are not connected by the X2 interface, and the EPC function units 3 (A) and 3 (B) corresponding to the core network are independent of each other. Therefore, the above-mentioned conventional form of handover control is not performed. Instead of this, a unique simple handover process is performed, which will be described in detail later.

FIG. 3 is a block diagram showing an electrical configuration of the wireless communication unit 1. The EPC function unit 3 is mainly composed of microcomputer hardware, and stores CPU 301, RAM 302 as a program execution area, and mask ROM 303 (firmware for peripheral control of microcomputer hardware that does not need to be permanently rewritten; The same applies hereinafter) and the bus 306 and the like connecting them to each other. Further, a flash memory 305 is connected to the bus 306, and the communication firmware 305a including the LTE protocol stack for EPC and the MME2, S-GW6, and P-GW7 of FIG. 2 using the LTE protocol stack as a platform are used. The programs of MME entity 305b, S-GW entity 305c, and P-GW entity 305d that virtually realize the functions are installed. Further, the flash memory 305 also stores a transfer table 305e, a transfer table update program 305f, and a channel map 305g for performing transfer routing of IP packets.

Further, the network adjustment program 305h is stored in the flash memory 305. The program 305h has a function of instructing the radio base station unit 4 to temporarily and forcibly disconnect the radio bearer between downstream units with the downstream unit (the specific processing flow thereof is , FIG. 33 and FIG. 34).

Further, the upstream communication interface 304A and the downstream communication interface 304B are connected to the bus 306. The input / output port of the IP packet for P-GW is secured on the upstream communication interface 304A, and the input / output port of the IP packet for S-GW is secured on the downstream communication interface 304B. In the above configuration, the MME2, S-GW6, and P-GW7 shown in FIG. 2 are configured as virtual function blocks on the computer hardware, but they may be configured by independent hardware logic.

The radio base station section 4 is mainly composed of microcomputer hardware, and includes a CPU 401, a RAM 402 as a program execution area, a mask ROM 403, a bus 406 connecting them to each other, and the like. A flash memory 405 is connected to the bus 406, and communication firmware 405a including an LTE protocol stack for a radio base station is stored therein. Further, a communication interface 404 is connected to the bus 406 with a wireless communication unit 412 for wirelessly connecting to the UE by constructing a wireless bearer for terminals. The communication interface 404 is connected to the downstream communication interface 304B of the EPC function unit 3 by a wired communication bus 31.

Further, there are a plurality of relay wireless communication units, and two sets of 9 (A1) and 9 (A2) are provided in FIG. 3, all of which are mainly composed of microcomputer hardware and have the same electrical configuration. There is. Therefore, on the other hand, it will be described as a representative (hereinafter, both relay wireless communication units are collectively referred to as a relay wireless communication unit 9). The relay wireless communication unit 9 includes a CPU 901, a RAM 902 that serves as a program execution area, a mask ROM 903, and a bus 906 that connects them to each other. A flash memory 905 is connected to the bus 906, and a communication firmware 905a including an LTE protocol stack for the relay wireless communication unit and an upstream unit connection switching control program 905b are stored therein. Further, a communication interface 904 is connected to the bus 906 with a wireless communication unit 912 for wirelessly connecting to the upstream wireless base station unit by constructing an inter-unit wireless bearer. The communication interface 904 is connected to the upstream communication interface 304A of the EPC function unit 3 by a wired communication bus 30.

In the relay wireless communication unit 9, the LTE protocol stack for the relay wireless communication unit incorporated in the communication firmware 905a is the same as the protocol stack for the UE (mobile terminal) described later. In other words, the connection procedure of the relay radio communication unit 9 to the upstream radio base station unit is formally the same as the attach sequence, which is the connection procedure of the UE (mobile terminal). Further, the upstream unit connection switching control program 905b has higher quality when the relay wireless communication unit 9 attaches to the wireless base station unit of the upstream unit and there are two or more wireless communication units as connection destination candidates. The process of selecting the wireless communication unit that can be connected as the upstream unit to be finally connected, or the switching candidate unit that is different from the upstream unit and can be wirelessly connected with higher quality than the upstream unit If it exists, it is responsible for switching the connection to the switching candidate unit as a new upstream unit.

Further, a router 8 that relays transmission / reception of IP packets between the EPC function unit 3 and an external network 60 such as the Internet is connected to the communication bus 30 (that is, the EPC function unit 3 and the relay wireless communication unit 9). A router 8 is provided between the and.

Next, the wireless communication unit 1 includes a detachable secondary battery module 21 (for example, a lithium ion secondary battery module, a nickel hydrogen secondary battery module, etc.), a wireless base station unit 4, an EPC function unit 3, a router 8, and the like. Each functional circuit block of the relay wireless communication unit 9 and the power supply circuit unit 22 that converts the input voltage from the secondary battery module 21 into the drive voltage of each functional circuit block and outputs it are integrated in the portable housing 23. It has an assembled structure. As a result, the wireless communication unit 1 can autonomously procure the drive power supply voltage from the secondary battery module 21, and can be used without problems even in an installation place (for example, at sea) where the external power supply voltage cannot be used such as commercial AC. is there. The portable housing 23 is a box type made of metal or reinforced resin, and in the example shown in FIG. 3, the casters 24C are pushed to the bottom of the portable housing 23 and also to the back for convenience of transportation or movement. A handle 24 for use is provided.

When the output voltage of the secondary battery module 21 drops due to discharge, the secondary battery module 21 is removed from the portable housing 23 and attached to, for example, a commercial AC power supply (not shown) or a dedicated charger connected to a private power generator. It is possible to charge the battery. Further, the power supply circuit unit 22 can also receive an external power supply voltage such as the commercial alternating current or a centralized power supply unit provided on the mobile body, and can convert and output the drive power supply voltage. Further, it can be configured so that the secondary battery module 21 can be charged by the external power supply voltage. For example, if the power supply circuit unit 22 is receiving power from commercial AC or the like and the power reception is interrupted due to a power failure, the operation of the wireless communication unit 1 can be continued by switching to receiving power from the secondary battery module 21. It can also be configured as follows.

Next, FIG. 4 is a block diagram showing an example of the electrical configuration of the UE (mobile terminal) 5. The UE 5 is configured as a smartphone including the microcomputer 100 as a processing subject. The microcomputer 100 includes a CPU 101, a RAM 102 and a ROM 103 that serve as a program execution area, an input / output unit 104, and a bus 106 that connects them to each other. Further, a flash memory 105 is connected to the bus 106, and an OS (not shown) for constructing an operating environment for the UE 5 and a terminal application 105b or the like are installed therein.

A monitor 109 is connected to the input / output unit 104 via a graphic controller 1091. A touch panel 110 forming an input unit is superposed on the monitor 109, and cooperates with various software operation units (buttons, icons, etc .: see FIGS. 13 to 17) displayed and formed on the monitor 109 to control the operation of the UE 5. Various necessary information can be input. The touch panel 110 is connected to the input / output unit 104 via the touch panel controller 1101. A camera 111 for shooting a still image or a moving image is connected to the input / output unit 104. Further, a wireless communication unit 112 is connected to the bus 106. The UE 5 is wirelessly connected by the wireless communication unit 112 to the wireless base station unit 4 of the wireless communication unit 1 of FIG. 2 via the terminal wireless bearer 57.

FIG. 5 is a schematic diagram showing a structure of an IP packet used for data transmission between the UE 5 and the wireless communication unit 1. The IP packet 1300 includes an IP header 1301 and a payload 1302, and a PDU identification number, a data source address 1301a, a destination address 1301b, and the like are written in the IP header 1301.

6 and 7 show the radio protocol stack in the LTE system, FIG. 6 shows the protocol stack in the user plane, and FIG. 7 shows the protocol stack in the control plane. The radio protocol stack is divided into layers 1 to 3 of the OSI reference model, and layer 1 is a PHY (physical) layer. The layer 2 includes a MAC (Medium Access Control) layer, an RLC (Radio Link Control) layer, and a PDCP (Packet Data Convergence Protocol) layer. Layer 3 includes an RRC (Radio Resource Control) layer and a NAS (Non-Access Stratum) layer.

The role of each layer is as follows.
-PHY layer: Performs encoding / decoding, modulation / demodulation, antenna mapping / demapping, and resource mapping / demapping. Data and control signals are transmitted between the PHY layer of the UE 5 and the relay radio communication unit 9 and the PHY layer of the radio base station unit (eNodeB) 4 via a physical channel.
-MAC layer: Performs data priority control, retransmission control processing by HARQ, random access procedure, and the like. Data and control signals are transmitted between the MAC layer of the UE 5 and the relay radio communication unit 9 and the MAC layer of the radio base station unit 4 via a transport channel. The MAC layer of the radio base station unit 4 includes a scheduler that determines the transport format (transport block size, modulation / coding method (MCS)) of the upper and lower links and the resource block allocated to the UE 5.

RLC layer: Data is transmitted to the receiving RLC layer by using the functions of the MAC layer and the PHY layer. Data and control signals are transmitted between the RLC layer of the UE 5 and the RLC layer of the radio base station unit 4 via a logical channel.
-PDCP layer: Compresses / decompresses the header of the PDU, and encrypts / decrypts it.
RRC layer: Defined only in the control plane that handles control signals. Messages for various settings (RRC messages) are transmitted between the RRC layer of the UE 5 and the RRC layer of the radio base station unit 4. The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, reestablishment, and release of radio bearers. If there is a connection (RRC connection) between the RRC of the UE 5 and the RRC of the radio base station unit 4, the UE 5 is in the RRC connected mode, otherwise it is in the RRC idle mode.

The above layers are used in both the control plane and the user plane. On the other hand, only the control plane, the UE 5, the relay radio communication unit 9, and the MME 2 are provided with a NAS layer that performs session management, mobility management, and the like above the RRC layer. Further, a GTP-U (GPRS (General Packet Radio Service) Tunneling Protocol for User Plane) layer is provided on the user data transmission interface with the EPC function unit 3 side of the radio base station unit 4. The GTP-U layer is for identifying the UE 5 to be connected to or the relay wireless communication unit 9 and the wireless bearer to be used.

Next, FIG. 8 shows downlink channel mapping in the LTE system. Here, the mapping relationship between the logical channel (Downlink Logical Channel), the transport channel (Downlink Transport Channel), and the physical channel (Downlink Physical Channel) is shown. Hereinafter, they will be described in order.
-DTCH (Dedicated Traffic Channel) is an individual logical channel for transmitting data. The DTCH is mapped to a DLSCH (Downlink Shared Channel) which is a transport channel.

-DCCH (Dedicated Control Channel): A logical channel for transmitting individual control information between the UE 5 and the network. The DCCH is used when the UE 5 and the relay radio communication unit 9 have an RRC connection with the radio base station unit 4. The DCCH is mapped to the DLSCH.
CCCH (Common Control Channel): A logical channel for transmission control information between the UE 5 and the relay radio communication unit 9 and the radio base station unit 4. CCCH is used when the UE 5 and the relay radio communication unit 9 do not have an RRC connection with the radio base station unit 4. CCCH is mapped to DLSCH.

-BCCH (Broadcast Control Channel): A logical channel for system information distribution. BCCH is mapped to BCH (Broadcast Channel) or DLSCH which is a transport channel.
-PCCH (Paging Control Channel): A logical channel for notifying changes in paging information and system information. PCCH is mapped to PCH (Paging Channel) which is a transport channel.

The mapping relationship between the transport channel and the physical channel is as follows.
-DLSCH and PCH: Mapped to PDSCH (Physical Downlink Shared Channel). DLSCH supports HARQ, link adaptation, and dynamic resource allocation.
-BCH: Mapped to PBCH (Physical Broadcast Channel).

Next, FIG. 9 shows uplink channel mapping in the LTE system. Similar to FIG. 8, the mapping relationship between the logical channel (Downlink Logical Channel), the transport channel (Downlink Transport Channel), and the physical channel (Downlink Physical Channel) is shown. Hereinafter, they will be described in order.

-CCCH (Common Control Channel): A logical channel used for transmitting control information between the UE 5 and the relay radio communication unit 9 and the EPC function unit 3, and is a logical channel used between the EPC function unit 3 and the radio resource. Used by UE5 that does not have a Control (RRC) connection.
-DCCH (Dedicated Control Channel): A one-to-one (point-to-point) bidirectional logical channel, and individual control information between the UE 5 and the relay radio communication unit 9 and the EPC function unit 3. This is the channel used to send. The dedicated control channel DCCH is used by the UE 5 which has an RRC connection.
DTCH (Dedicated Traffic Channel): A one-to-one bidirectional logical channel, which is a channel dedicated to a specific UE or relay radio communication unit, and is used for transferring user information.

-ULSCH (Uplink Shared Channel): HARQ), dynamic adaptive radio link control, and intermittent transmission (DTX: Discontinuous Transmission) are supported transport channels.
-RACH (Random Access Channel): A transport channel through which restricted control information is transmitted.

-PUCCH (Physical Uplink Control Channel): Response information (ACK (Acknowledge) / NACK (Negative acknowledge)) for downlink data, downlink radio quality information (CQI), and uplink data. This is a physical channel used to notify the radio base station unit 4 of a transmission request (scheduling request: SR).
-PUSCH (Physical Uplink Shared Channel): A physical channel used for transmitting uplink data.
-PRACH (Physical Random Access Channel): A physical channel mainly used for random access preamble transmission for acquiring transmission timing information (transmission timing command) from the UE 5 to the radio base station unit 4. Random access preamble transmission is performed in a random access procedure.

As shown in FIG. 9, in the uplink, the transport channel and the physical channel are mapped as follows. The uplink shared channel ULSCH is mapped to the physical uplink shared channel PUSCH. The random access channel RACH is mapped to the physical random access channel PRACH. The physical uplink control channel PUCCH is used by the physical channel alone. Further, the common control channel CCCH, the dedicated control channel DCCH, and the dedicated traffic channel DTCH are mapped to the uplink shared channel ULSCH.

Next, in the downlink of the LTE system, the UE 5 and the relay radio communication unit 9 wirelessly connect to the radio base station unit 4 by OFDM (Orthogonal Frequency-Division Multiplexing) access (OFDMA). The OFDMA system is characterized as a two-dimensional multiplexed access system in which frequency division multiplexing and time division multiplexing are combined. Specifically, the orthogonal frequency axis and time axis subcarriers are divided and assigned to the UE 5, and the orthogonal subcarriers on the frequency axis are divided so that the signal of each subcarrier becomes zero (0 point). .. By dividing the subcarriers and assigning them on the frequency axis, one subcarrier can select another subcarrier that is not affected by fading, so that the user is better depending on the wireless environment. There is an advantage that the subcarrier can be used and the radio quality can be maintained.

Then, in the OFDMA method, a resource block (hereinafter, also referred to as RB) defined on a virtual plane where the frequency axis and the time axis are stretched is adopted as a radio resource. As shown in FIG. 10, RB is defined as a block in which the plane is divided into a matrix at 180 kHz / 0.5 msec, and each block has 12 adjacent subcarriers at 15 kHz intervals on the frequency axis and 12 adjacent subcarriers on the time axis. Includes 1 slot (7 symbols) of the frame. This RB is assigned to the UE 5 and the relay radio communication unit 9 as a set of two adjacent (1 msec) on the time axis. On the other hand, in the uplink of the LTE system, a resource block of the same concept is used as a radio resource except that SC-FDM (Single Career Frequency-Division Multiplexing) access (SC-FDMA) is adopted. In OFDMA, one resource block is divided into 12 subcarriers (bandwidth: 15 kHz) on the frequency axis, whereas SC-FDMA is a single carrier system in which division into subcarriers is not performed.

For example, the allocation of a resource block to a downlink is determined by the following procedure in a normal LTE protocol. The UE 5 and the relay radio communication unit 9 receive the CQI reference signal transmitted from the eNodeB 4 for each defined frequency unit, measure the CQI which is an indicator indicating the reception quality of the downlink channel, and create the CQI information. .. As shown in FIG. 32, the CQI information represents the reception quality obtained by the measurement with two parameters of the coding rate and the frequency utilization efficiency for each modulation method, and indicates the uplink control channel (PUCCH described above). It is reported from UE5 to eNodeB4 using the CQI index.

The eNodeB 4 is assigned to a wireless bearer with each UE 5 or the relay radio communication unit 9 based on the CQI information notified from the plurality of UEs 5 or the relay radio communication unit 9. By optimally allocating a frequency block having a high received signal level to each UE 5 and the relay radio communication unit 9 according to the contents of the CQI information of each UE 5 and the relay radio communication unit 9, the UE 5 and the relay radio communication unit 9 are allocated. The diversity effect of 9 (multi-user diversity) can be obtained, and the user throughput and the throughput per cell can be improved.

FIG. 11 shows a configuration example of the wireless network system of the present invention when the wireless communication unit 1 having the above configuration is adopted. In the wireless network system, the wireless communication unit groups 1 (A) to 1 (D) have a pair of wireless communication units (1 (A) and 1 (B), 1 (B) and 1 (C), 1 ( In a positional relationship in which the base station cells (50 (A) and 50 (B), 50 (B) and 50 (C), 50 (B) and 50 (D)) of B) and 1 (D) partially overlap. , The unit-to-unit wireless bearers 55 (A), 55 (B), 55 (D) are connected. Further, the relay wireless communication unit 9 (B1) of the wireless communication unit 1 (B) is also connected to the wireless base station unit 4 (D) of the wireless communication unit 1 (D) by the inter-unit wireless bearer 55 (D). 9 (B2) is independently and individually connected to the radio base station unit 4 (C) of the radio communication unit 1 (C) by the inter-unit radio bearer 55 (B).

For example, the plurality of relay radio communication units 9 (B1) and 9 (B2) of the radio communication unit 1 (B) are upstream radio base station units that are different from each other, that is, radio base station unit 4 (D) and radio base station unit 4 (C). ) Is connected to the upstream unit radio bearers 55 (D) and 55 (B), but the upstream unit radio bearers 55 (D) and 55 (B) are constructed using different frequency channels CH5 and CH2. Has been done. Further, the inter-unit radio bearer 55 (A) is set to a frequency channel (CH1 in FIG. 11) different from any of these. Further, when viewed from the wireless communication unit 1 (B), the downstream inter-unit wireless bearer 55 (A) and the upstream inter-unit wireless bearer 55 (B), 55 (D) have different frequency channels (CH1 and CH2, CH5 in FIG. 11). ) Is set. On the other hand, in the connection form shown in FIG. 2, for example, between the downstream units of the two wireless communication units 1 (A) and 1 (C) that are simultaneously connected to the wireless base station unit 4 (B) of the wireless communication unit 1 (B). The wireless bearers 55 (A) and 55 (B2) can be constructed using the same frequency channel.

For example, the UE 5 (A) (mobile terminal) connected to one of the wireless communication units 1 (A) and 1 (B) and the UE 5 (B) (mobile terminal) connected to the other are wireless communication units 1: 1. IP packets can be transmitted and received via the inter-unit wireless bearer 55 (A) connecting the wireless communication units (A) and 1 (B) and the wireless communication units 1 to 1 (A) and 1 (B). All of the wireless communication unit groups 1 (A) to 1 (D) may be mounted on the mobile body such as the above-mentioned ship or vehicle, or only some of them may be mounted on the mobile body. The remaining items may be fixedly installed in the building or the like.

In the wireless communication system of the 3GPP specification, any of the plurality of frequency bands specified in the 3GPP is assigned. The assigned frequency band differs depending on the communication method. For example, bands 1, 3, 6, 8, 11, 18, 19, 21, 26, 28, 41 and 42 are used as LTE bands. Each band is divided into a plurality of frequency channels having a predetermined bandwidth, and the EPC function unit 3 selects a predetermined frequency channel for the inter-unit radio bearer 55 and the terminal radio bearer 57 shown in FIG. Will be built. That is, the downstream inter-unit channel, the upstream inter-unit channel, and the terminal side channel are each set as a frequency channel belonging to any of a plurality of bands defined in 3GPP.

In the present embodiment, the EPC function unit 3 fixedly sets the set frequency channel of the (downstream) inter-unit radio bearer 55 to the (downstream) inter-unit channel, which is a specific predetermined frequency channel. Further, the terminal side channel, which is the set frequency channel of the terminal wireless bearer 57, is set to the same frequency channel as the (downstream) inter-unit channel. That is, the EPC function unit 3 sets the same frequency channel for the relay wireless communication unit 9 and the mobile terminal 5 of the wireless communication unit 1 on the downstream side for the wireless base station unit 4 directly underneath.

The wireless bearer 57 for terminals appropriately changes the number of frequency channels used in the same band according to the number of UEs 5 connected to the wireless base station 4 and the congestion status of communication traffic due to the capacity of transmitted data. There is a need to. Further, when the UE moves between cells having overlapping of adjacent wireless communication units, the frequency channel used by the terminal wireless bearer 57 when connecting to each wireless base station portion between the cell before the movement and the cell after the movement is changed. If they are the same, the problem of cell-to-cell interference arises. Therefore, when the UE (mobile terminal) 5 moves to the cell on the downstream side, the UE (mobile terminal) 5 has the radio base station unit 4 of the wireless communication unit 1 of the destination cell between the (downstream) units as seen from the wireless base station unit 4. The handover process described later is performed in the form of switching to the set frequency channel (channel between (downstream) units) of the wireless bearer 55. On the other hand, when the UE (mobile terminal) 5 moves to the cell on the upstream side, the (upstream) unit-to-unit radio seen from the radio base station unit 4 with respect to the radio base station unit 4 of the radio communication unit 1 of the destination cell. The handover process described later is performed in the form of switching to the set frequency channel (channel between (upstream) units) of the bearer 55. That is, as the UE (mobile terminal) 5 moves between cells, the terminal wireless bearer 57 is constructed by sequentially switching the terminal side channels. However, with respect to the inter-unit wireless bearer 55, the transmission of IP packets from each communication unit 1 to which a large number of UEs 5 are connected is aggregated and the amount of communication traffic becomes very large, so that the IP packet transmission process is as smooth as possible. Is required to do. At this time, if the frequency channel setting of the inter-unit wireless bearer 55 is frequently changed according to the connection status of the UE 5 in each cell, IP packet transmission across the plurality of wireless communication units 1 is performed. When trying to do so, problems such as communication interruption in the wireless bearer 5 between units are likely to occur.

In the configuration of a wireless network system that connects a plurality of wireless communication units 1 (A) to 1 (D) as shown in FIG. 11, the connection topology of the adjacent unit by the inter-unit wireless bearer 55 with the wireless base station unit 4 is large. If it does not change, the wireless base station unit 4 to which the relay wireless communication unit 9 of each wireless communication unit 1 is connected is fixed, and the handover process involving frequency channel switching is unnecessary for the relay wireless communication unit 9. Become. Therefore, by fixedly setting the inter-unit wireless bearer 55 to the inter-unit channel, which is one specific frequency channel defined in advance, it is possible to effectively prevent communication interruption due to channel switching of the inter-unit wireless bearer 55. , The stability of IP packet transmission when crossing a plurality of wireless communication units 1 can be significantly improved.

Each EPC function unit 3 of the wireless communication units 1 (A) to 1 (D) sets a channel between downstream units with respect to the wireless bearer between upstream units when the wireless bearer between (upstream) units is constructed. While the frequency channel is set to be different from the upstream inter-unit channel, the terminal channel group is set as a frequency channel group different from both the downstream inter-unit channel and the upstream inter-unit channel. For example, when focusing on the wireless communication unit 1 (B), the EPC function unit 3 of the wireless communication unit 1 (B) is set for the upstream unit wireless bearers 55 (B) and 55 (D). The upstream unit-to-unit channels are set to, for example, CH2 and CH5, respectively. On the other hand, the EPC function unit 3 of the wireless communication unit 1 (A) is located between the upstream unit wireless bearers 55 (A) seen from the wireless communication unit 1 (A) (between the downstream units when viewed from the wireless communication unit 1 (B)). The upstream unit-to-unit channel (which is a downstream unit-to-unit channel when viewed from the wireless communication unit 1 (B)) set for (which is a wireless bearer) is set to CH1 which is different from CH2 and CH5. At this time, by setting the downstream inter-unit channel CH1 and the upstream inter-unit channels CH2 and CH5 as different frequency channels in the same band, the radio base station unit 4 and the relay radio communication unit for constructing the inter-unit radio bearer are set. There is an advantage that the hardware of 9 can be easily configured with a single band specification.

Further, the terminal side channel is set to the same channel as the downstream unit-to-unit channel among the frequency channels belonging to the same band. For example, when only one band is assigned to the entire wireless network system of FIG. 11, the terminal side channel is a terminal by setting the same channel as the downstream unit-to-unit channel among the frequency channels belonging to the same band. The hardware of the radio base station unit 4 and the relay radio communication unit 9 can be made into a single band specification including the construction of a wireless bearer for use, which contributes to simplification of the device configuration. The terminal-side channel may be switchably selected from the remaining frequency channels other than those set as the downstream unit-to-unit channel and the upstream-unit-to-unit channel.

Further, in the present embodiment, the band 28 defined in 3GPP is adopted as the same band as described above. The band 28 is set to the VHF band (700 MHz band), which is vacant due to the stoppage of terrestrial analog television broadcasting. Since band 28 is a low frequency band, the communication speed is somewhat slow, so adoption in areas with many terminal subscribers such as urban areas is not being actively promoted, and the usage status of radio wave resources is so tight. Since there is no such thing, smooth connection can be expected. Further, the low frequency band is excellent in the distant reachability of radio waves, and the area (cell) that can be covered by one wireless communication unit can be expanded. In addition, it has the property of being easily connected even if there are underground or obstacles, and can be said to be suitable for constructing the wireless network system of the present invention, for example, at sea or in a mine.

Next, in the wireless network system of the present invention, the inter-unit wireless bearers that are adjacent to each other in the upstream / downstream positional relationship with respect to the wireless communication unit as shown in FIG. 11, for example, the inter-unit wireless bearers 55 (A), 55 in FIG. As a specific method for making the inter-unit channel settings of B) and 55 (D) different from each other, for example, via the inter-unit wireless bearers 55 (A), 55 (B), 55 (D), respectively. This can be performed by the wireless communication units 1 (A) to 1 (D) sharing channel information between units.

When the upper limit of the number of wireless communication units participating in the wireless network system is set, it depends on the combination of node addresses assigned to the individual wireless communication units 1 (A) to 1 (D) in FIG. Therefore, it is effective to uniformly determine the types of inter-unit channels to be allocated in the form of a channel map and incorporate this channel map into the EPC function unit 3 of each wireless communication unit in order to further simplify the process. Is. Even if each EPC function unit 3 does not share channel setting information with the EPC function unit 3 of another wireless communication unit, the inter-unit channel of the adjacent inter-unit wireless bearer is different by referring to the built-in channel map. It is possible to set so as to be. In this case, the EPC function unit 1 stores a channel map storage unit that stores a channel map showing the correspondence between the frequency channel group that can be selected as the channel between downstream units and the node address of the downstream relay radio communication unit that is the connection destination. In response to an attach request from the downstream relay radio communication unit, the node address of the downstream relay radio communication unit is acquired, and the frequency channel corresponding to the acquired node address is specified on the channel map to be specified. It operates so as to set the frequency channel as a channel between downstream units.

FIG. 12 shows an example of the channel map 305 g. The channel map 305g exemplifies a case where the number of wireless communication units 1 participating in the system construction is four, and each wireless communication unit 1 is assigned node addresses MID01 to MID04 (in FIG. 11). Wireless communication units 1 (A), 1 (B), 1 (C) and 1 (D) correspond in this order). Then, depending on the combination of these node addresses, the channel numbers of the inter-unit channels set between the corresponding wireless communication units 1 are defined so as not to be duplicated. The channel map 305g is updated as needed as the number of wireless communication units 1 increases or decreases and the arrangement is changed.

FIG. 13 is a flowchart showing the flow of the channel setting process using the channel map 305 g by the EPC function unit 3. In B101, the channel number CH # M of the channel between the downstream units is acquired from the node address of the wireless communication unit on the downstream side with reference to the channel map 305 g. In B102, the channel number CH # B (the channel number CH # B may be plural) of the channel between units on the upstream side is acquired from the wireless communication unit on the upstream side. In B103, the channel numbers CH # U1, CH # U2, ... For the UE are selected from the remaining channel numbers other than CH # M / CH # B. Then, in B104, the available channel numbers (CH # U1, CH # U2 ...) Are notified to the radio base station unit and the UE. This notification is executed by the attachment sequence of the radio base station and the UE.

Hereinafter, the flow of the attachment sequence of the relay wireless communication unit 9 and the UE 5 will be described with reference to FIGS. 14 and 15. FIG. 14 shows an attachment sequence of the relay wireless communication unit 9. In the present embodiment, each wireless communication unit 1 is equipped with two relay wireless communication units, but "relay wireless communication unit 9" means any one of them, and all of them are of the other wireless communication units 1. It can be attached independently to the radio base station unit 4. In the TS1, an attach request is issued from the relay radio communication unit 9 to the MME 2 via the radio base station unit (eNodeB) 4. By receiving the notification signal periodically output from the eNodeB 4, the relay wireless communication unit 9 can recognize that it has entered the cell (that is, within the range) of the eNodeB 4, and outputs the attach request to the eNodeB 4. At this time, the IP address of the wireless communication unit is transmitted to the requester. In response to this, the MME2 transmits a bearer setting request to the S-GW 6 on the TS2. The S-GW 6 executes a bearer setting process of a physical line on the S5 interface with the P-GW 7 at TS3. If the bearer is set, the S-GW 6 transmits a bearer setting response to the MME2 on the TS4.

The MME2 searches the TS5 for the wireless communication channel corresponding to the IP address of the requesting unit on the channel map 305 g (FIG. 12). Then, the TS6 notifies the radio base station unit 4 of the radio bearer setting request (attachment acceptance) together with the set channel number. Upon receiving this, the radio base station unit 4 transmits a MIB (Master Information Block) including a setting channel number of the radio bearer (inter-unit radio bearer) to be set by the TS 7 to the relay radio communication unit 9. In the TS8, the relay wireless communication unit 9 fixedly sets the inter-unit channel to the set channel number included in the received MIB, and returns the setting completion. In response to this, the radio base station unit 4 notifies the relay radio communication unit 9 of the session start request (touch acceptance) in TS9. In TS10, the relay radio communication unit 9 sets the radio bearer between units and returns the session start response to the radio base station unit 4. At TS11, the radio base station unit 4 notifies the MME2 of the session start response.

On the other hand, FIG. 15 shows the attachment sequence of the UE 5 (mobile terminal). In TS11', an attach request is issued from the UE 5 to the MME 2 via the radio base station unit (eNodeB) 4. At this time, the IP address of the wireless communication unit is transmitted to the requester. In response to this, the MME2 transmits a bearer setting request to the S-GW 6 on the TS12. The S-GW 6 executes a bearer setting process of a physical line on the S5 interface with the P-GW 7 at TS13. If the bearer is set, the S-GW 6 transmits a bearer setting response to the MME2 on the TS14. The MME 2 determines a set channel number that can be used as a wireless bearer group for terminals according to the process of FIG. Then, the TS16 notifies the radio base station unit 4 of the radio bearer setting request (attachment acceptance) together with the set channel number determined. Upon receiving this, the radio base station unit 4 transmits a MIB (Master Information Block) including a setting channel number of the radio bearer (inter-unit radio bearer) to be set in the TS 17 to the UE 5.

In TS18, the UE 5 sets the terminal-side channel to the set channel number included in the received MIB, and returns the setting completion. In response to this, the radio base station unit 4 notifies the UE 5 of the session start request (attachment acceptance) in TS19. At TS20, the UE 5 sets the radio bearer for the terminal and returns the session start response to the radio base station unit 4. At TS21, the radio base station unit 4 notifies the MME2 of the session start response. As described above, the attach sequence of the UE 5 and the attach sequence of the relay radio communication unit 9 are basically executed according to the same procedure except for the contents of the frequency channel setting.

In the LTE system, in order to flexibly change the transmission amount of the notification information such as the above-mentioned set channel number for each operation / environment, a fixed notification information resource using PBCH and a variable use using PDSCH can be used. Used in combination with wireless resources. Here, PBCH, which is a fixed resource, is used because the broadcast information is defined as the information first acquired by the UE 5 (relay radio communication unit 9), and the UE 5 (relay radio communication unit 9) uses the radio base station unit (relay radio communication unit 9). This is because it is necessary to be able to receive the notification without receiving the notification from eNodeB) 4. The UE 5 first receives the PBCH, which is a fixed resource, obtains the minimum information for receiving the PDSCH from the PBCH, and reads the broadcast information sent by the PDSCH based on the minimum information. Since the PDSCH is a variable resource that can be allocated in RB units, the amount of broadcast information transmitted by the PDSCH is variable. As a result, the amount of resources used for broadcast information can be changed, and wireless resources can be allocated according to the amount of broadcast information that differs depending on the network operation and environment.

Then, among the broadcast information transmitted by the PBCH, the above MIB is transmitted at the beginning of the radio frame (that is, the subframe number = 0), and the time resource and the frequency resource are always fixed. Assigned. The transmitted information is usually, for example, information for receiving other broadcast information (for example, SIB (System Information Block)) by PDSCH, radio frame number (SFN: System Frame Number), and the like. However, in the present embodiment, using this MIB, the radio base station unit 4 distributes the channel information of the terminal radio bearer or the unit-to-unit radio bearer to the UE 5 (relay radio communication unit 9). Although the size of the MIB is fixed at 24 bits, 10 bits of which are reserved areas, so that it is possible to incorporate the setting channel information of the wireless bearer, for example, by using this spare area.

Next, as shown in FIG. 11, each EPC function unit 3 of two or more wireless communication units 1 (A) to 1 (D) connected by the unit-to-unit wireless bearer 55 is individually connected to the wireless communication units 1 (A) to 1 (D). The addresses (terminal specific information) of UEs 5 (A), 5 (D), etc. (mobile terminals) connected to the wireless base station unit 4 of 1 (D) are set to the inter-unit wireless bearers 55 (A), 55 (B), It can be transferred to another wireless communication unit via 55 (D). As a result, between the wireless communication units 1 (A) to 1 (D) of the addresses of the UEs 5 (A) and 5 (D) connected between the two or more wireless communication units 1 (A) to 1 (D). Can be shared. Then, the EPC function unit 3 creates a forwarding table of IP packets based on the shared address (terminal specific information), and controls the forwarding of IP packets with reference to the forwarding table.

FIG. 16 shows an example of the transfer table 305e. The transfer table 305e is a connected terminal registration unit 305rt in which the addresses of UEs connected to itself (UEAD11, 12 ...) Are registered in a list, and adjacent units (upstream units and downstream units) that can be next hopping nodes. The adjacent unit list 305nt in which the node address of the unit) is registered, the address of the wireless communication unit that is the final transfer destination of the received packet, and the address of the wireless communication unit that is the next transfer destination of the received packet (unit). It includes a routing table 305ert stored in association with so-called next hopping). The adjacent unit list 305nt is for specifying the next hopping node to be registered in the routing table 305ert, and can be regarded as a part of the routing table 305ert in a broad sense.

In the wireless network system of the present embodiment, the information of the next hopping node is such that the wireless communication unit to which the UE to be the final packet transmission destination is connected is next hopping to the wireless communication unit adjacent to its own lower side. By notifying that it is a node and receiving this, the lower wireless communication unit performs the same notification to the lower wireless communication unit, so that the next hopping information for each wireless communication unit is the wireless communication of the packet source. It is transmitted sequentially to the unit. Each wireless communication unit writes the notified next hopping information to the routing table 305ert, and when a packet of the same destination is subsequently transmitted, the packet to the next wireless communication unit is referred to by referring to this routing table 305ert. The transfer runs smoothly. As for the contents of the routing table 305ert, a dynamic routing method is adopted, which is updated by a method described later at any time according to a change in the network topology.

FIG. 17 shows the flow of the update process of the adjacent node performed by each EPC function unit 3, and the update process of the transfer table 305e (FIG. 16) accompanying the update process. The process is realized by executing the transfer table update program 305f, and has the function of the transfer table update control unit. The outline is as follows.
(1) An IP packet transfer table is created based on the shared terminal identification information of the relay wireless communication unit, and the transfer control of the IP packet is performed with reference to the transfer table.
(2) When at least one of the number of wireless communication units included in the wireless network system and the connection order is changed, the contents of the transfer table are updated according to the changed contents.
As a result, the contents of the transfer table 305e are always maintained in the optimum state even when the topology of the connection state by the inter-unit bearer 55 is reversed due to the change in the number of wireless communication units 1 and the connection order. be able to.

First, when the process is started in A201, it is confirmed in A202 whether or not the arrangement (order and number) of the wireless communication units has changed. Specifically, it is confirmed whether the node address of the upstream unit or the downstream unit has changed due to the connection change described later, and if it has changed, the process proceeds to A203 and the contents of the adjacent unit list 305nt are updated. On the other hand, if it has not changed, A203 is skipped. In A204, the IP address of the UE connected to the local node is acquired. In A205, the contents of the connected terminal registration unit 305rt are updated by the acquired IP address. In A206, it is determined whether or not to end the process, and if not, the process returns to A202 after waiting for a certain period in A207, and the following process is repeated.

FIG. 18 shows the flow of the routing table update process in each wireless communication unit 1. The process is performed according to the so-called RIP (Routing Information Protocol). First, when a packet is received by A101, the connected terminal registration unit 305rt is referred to in A102 to determine whether or not the own node is the UE connection node (wireless communication unit to which the UE is connected) of the packet destination. To judge. If the local node is the UE connection node of the packet destination in A102, the process proceeds to A103 and the packet is transferred to the destination UE. Further, in A104, for all the adjacent nodes (generally, a plurality of) which are wireless communication units connected to itself, the local node is the connection node of the UE which is the final destination of the packet, that is, the destination node. , Notifies by transmitting the address of the own node (NHP address described later), and notifies in S105 that the number of hopping n is 1.

On the other hand, if the local node is not the UE connection node of the packet destination in A102, the process proceeds to A106 to refer to the routing table 305erf (FIG. 16), and whether the next hopping node corresponding to the destination node is registered in A107. To find out. If it is not registered, the process proceeds to A108, one of the adjacent nodes is defined as the next hopping node, and the node is registered in the routing table in association with the address of the destination node. On the other hand, if the next hopping node corresponding to the destination node is registered in A107, A108 is skipped. In either case, A109 performs a process of forwarding the packet to the next hopping node corresponding to the destination node.

In A110, a notification indicating that the node is the next hopping node from all the adjacent nodes to the destination node is received together with the node address (next hopping address: also referred to as NHP address) and the number of hopping n. In A111, it is checked whether or not the received hopping number n has a value smaller than the value registered in the routing table. If there is a hopping number smaller than the registered value, the process proceeds to A112, and the NHP address corresponding to the destination node and the hopping number are updated on the routing table using the received value. Then, in A113, all the adjacent nodes (excluding the adjacent nodes that have given the above notification) are notified that they are the next hopping node by transmitting the address (NHP address) of their own node, and the number of hoppings is further increased. 1 is added to the notification. If it does not end at A114, it returns to A101 and repeats the following processing.

According to RIP, as shown in FIG. 35, when the packet reaches the destination node, the destination node DT directs the own node to all the adjacent nodes NT11 to NT13 by the steps A104 and A105 of FIG. It notifies that it is a destination node by transmitting the NHP address, and further notifies that the number n of hopping (HP) is 1. Each of the adjacent nodes NT11 to NT13 that received this notification tells the adjacent node NT21 other than the source node of the notification that the own node is the next hopping node to the destination node DT (NHP address). Is notified by transmission of, and 1 is added to the received hopping number n to notify. When this process is sequentially executed for the subsequent adjacent nodes, the packet source node ST finally becomes each adjacent node corresponding to a plurality of routes from the destination node DT to the packet source node ST. The NHP address and the number of hopping numbers n1 to n3 are notified from NS1 to NS3, respectively. In the packet source node ST, the NHP address of the adjacent node corresponding to the route of the smallest of the hopping numbers n1 to n3 is associated with the address of the destination node DT together with the hopping number, and the routing table 305ert in FIG. Remember.

For example, in the example shown in FIG. 31, the number of wireless communication units 1 passing from the wireless communication unit 1 forming the source node ST to the wireless communication unit 1 forming the destination node DT, that is, the number of hopping is determined in the route RT1. 9, 6 for route RT2, 8 for route RT3, 9 for route RT4, but the information of the next hopping node of route RT2 that minimizes the number of hopping is automatically registered in the routing table of each node. It becomes. That is, the wireless communication unit that is the final transfer destination of the packet is the destination node DT, the plurality of wireless communication units 1 that reach the destination node DT are the relay node VT, and the next when the packet is transmitted to the destination node DT. With the wireless communication unit as the transfer destination as the next hopping node, each wireless communication unit 1 has a next hopping node corresponding to the destination node DT of the routing table so that the route is optimized in the direction in which the number of relay node VTs decreases. It is clear that the function of the routing table update unit for updating and setting the address of is provided. As a result, in a wireless network system in which a plurality of moving wireless communication units 1 are wirelessly connected, dynamic routing of packet transfer can be performed without any problem even if the connection topology changes.

Next, FIG. 19 shows a flow of transmission processing of IP packets between UEs 5 (UE (I) and UE (II)) connected to the same wireless communication unit 1. U1 and U2 are attachment sequences described with reference to FIG. 15, and a wireless bearer for a terminal is constructed. At U3, an IP packet is sent from the UE (I) to the radio base station unit 4 as an uplink packet. The radio base station unit 4 transfers this to the EPC function unit 3. The EPC function unit 3 refers to the connected terminal registration unit 305rt in FIG. 16, and transmits the IP address of any UE connected to the wireless communication unit to which the EPC function unit 3 belongs, which is recorded in the header of the received IP packet. Check if it matches the destination address. In the case of FIG. 19, the IP address of the UE (II) corresponds to this, and the IP packet is transferred back to the subordinate radio base station 4 as a downlink packet at D1. The radio base station unit 4 receives this and transfers it to the UE (II), and the process is completed.

FIG. 20 shows an IP packet transmission process between the UE 5 (A) connected to the wireless communication unit 1 (A) in FIG. 11 and the UE 5 (B) connected to the adjacent wireless communication unit 1 (A). It shows the flow. The processing from U1 to U3 is the same as that in FIG. In U3, the EPC function unit 3 of the wireless communication unit 1 (A) refers to the connected terminal registration unit 305rt, and the destination address of the received IP packet is any of the wireless communication unit 1 (A) to which it belongs. It is confirmed that the next hopping is the wireless communication unit 1 (B) on the upstream side by referring to the routing table 305ert, which does not match the IP address of the UE of. Then, the U4 transfers the IP packet to the wireless communication unit 1 (B) on the upstream side by the inter-unit wireless bearer 55 (A). The wireless communication unit 1 (B) receives this IP packet, similarly refers to the connected terminal registration unit 305rt, and confirms that the IP address of the UE 5 (B) matches the IP address of the transmission destination. Then, D2 transfers the IP packet as a downlink packet to the subordinate radio base station unit 4. The radio base station unit 4 receives this and transfers it to the UE 5 (B), and the process is completed.

For example, the UE that is the source of the IP packet is connected to an intermediate one of the connected wireless communication units, and the UE that is the destination is connected to the wireless communication unit that is downstream from the wireless communication unit. If, the EPC function unit 3 refers to the connected terminal registration unit 305rt in the above UE, and the destination address of the received IP packet is the IP address of any UE connected to the wireless communication unit to which it belongs. Also, by referring to the routing table 305ert, it is confirmed that the next hopping is the wireless communication unit on the downstream side. Then, the IP packet is transferred to the radio base station unit 4 as a downlink packet, and further transferred to the radio communication unit to which the UE as the transmission destination is connected by using the inter-unit radio bearer on the downstream side.

FIG. 21 shows an IP packet between the UE 5 (A) connected to the wireless communication unit 1 (A) and the UE 5 (C) connected to the wireless communication unit 1 (C) two ahead in FIG. It shows the flow of transmission processing. The processing from U1 to U4 is the same as in FIG. In U5, the EPC function unit 3 of the wireless communication unit 1 (B) refers to the connected terminal registration unit 305rt, and the destination address recorded in the header of the received IP packet is the wireless communication unit 1 (B) to which it belongs. ), It is confirmed that the IP address does not match any of the UEs connected to), and the IP packet is transferred to the wireless communication unit 1 (C) on the upstream side by the inter-unit wireless bearer 55 (B) at U5. The wireless communication unit 1 (C) receives this IP packet, similarly refers to the connected terminal registration unit 305rt, and confirms that the IP address of the UE 5 (C) matches the IP address of the transmission destination. Then, D3 transfers the IP packet as a downlink packet to the subordinate radio base station unit 4. The radio base station unit 4 receives this and transfers it to the UE 5 (C), and the process is completed.

Further, each of the wireless communication units 1 (A) to 1 (D) in FIG. 11 has a built-in router 8 and can be connected to an external network 60 (for example, a global public network (Internet)) by, for example, a satellite communication line 61 or the like. Is. With this configuration, it is possible to transfer an IP packet to a network other than the wireless network system of the present invention as a transmission destination. In FIG. 11, the router 8 of the wireless communication unit 1 (D) is connected to the external network 60.

Next, the above-mentioned simple handover process will be described.
As already described with reference to FIG. 2, in the present embodiment, one wireless communication unit 1 (A) and the other wireless communication unit 1 (B) forming a wireless communication unit pair are formed only by the inter-unit wireless bearer 55. It is configured to be connected by communication. That is, the control interface for directly connecting the wireless communication units 1 (A) and 1 (B) between the radio base station units 4 and 4 is omitted (that is, the conventional X2 interface is not provided). .. Therefore, when the mobile terminal 5 (A) connected to the wireless communication unit 1 (A) in FIG. 11 moves into the communication cell 50B of the wireless communication unit 1 (B), a normal handover process using the X2 interface is performed. Cannot be implemented. Therefore, in the present embodiment, the following simple handover process is executed according to the sequence shown in FIG. That is, the UE 5 (A) executes the attach sequence shown in FIG. 15 in U1 and U2 with respect to the wireless communication unit 1 (A), and constructs a terminal wireless bearer with the wireless communication unit 1 (A). As a result, the UE 5 (A) can send and receive uplink packets (U3) and downlink packets (D1) to and from the wireless communication unit 1 (A).

Then, in S101, the UE 5 (mobile terminal) detects the disconnection of the terminal wireless bearer that connects the wireless base station unit 4 of the wireless communication unit 1 (A) and the UE 5 (mobile terminal), and further, in S102, the destination radio is detected. When the UE 5 detects the communication unit 1 (B), the UE 5 makes a new attach request to the wireless communication unit 1 (B) at U1'. Upon receiving this attach request, the wireless communication unit 1 (B) establishes a new terminal wireless bearer with the UE 5 based on the same processing as U2. That is, based on the command from the EPC function unit 3 of the wireless communication unit 1 (B), the terminal between the wireless base station unit 4 of the wireless communication unit 1 (B) and the UE 5 (A) (mobile terminal) after the movement. The wireless bearer for is rebuilt. From the above processing, it can be seen that, despite the environment in which the inter-base station interface does not exist, the substantial handover processing associated with the inter-cell movement of the UE 5 can be realized.

Hereinafter, a specific example in which the topology of the wireless communication unit connection in the system is changed while the wireless network system of the present invention is constructed will be described. Here, an example is taken in which the upper limit of the number of other wireless communication units (relay wireless communication units) that can be connected to the wireless base station unit of one wireless communication unit is set to 2. In the state A1 of FIG. 23, the three wireless communication units 1 (B) to 1 (D) are connected by the inter-unit wireless bearers 55 (B) and 55 (C). In the eNodeB 4 of the wireless communication unit 1 (B), other wireless communication units are not connected, and up to two new wireless communication units can be connected.

Further, a plurality of (two in this case) relay wireless communication units 9 (denoted as A1 / A2, B1 / B2, etc. in the figure) of each wireless communication unit 1 (B) to 1 (D) are wireless. Regarding the communication units 1 (B) to 1 (C), one is attached to the radio base station section 4 of the upstream unit, and the other is not connected. Further, in the wireless communication unit 1 (D) at the end, all the relay wireless communication units 9 are not connected. These unconnected relay wireless communication units 9 can be attached to the wireless base station unit of the wireless communication unit if there is another connectable wireless communication unit. At this time, identification IDs are assigned to the plurality of relay wireless communication units 9 belonging to the same wireless communication unit 1, and when attaching to another wireless communication unit, which relay wireless communication unit 9 is preferentially attached. The attachment order indicating whether to proceed is determined between the identification IDs (in the present embodiment, the attachment order of the relay wireless communication unit 9 having a small number indicated by the identification ID is determined to be higher). Further, when a plurality of relay wireless communication units 9 are not connected and there are a plurality of candidates for the wireless communication unit to be attached, the relay wireless communication unit 9 having the higher attachment order is indicated by the CQI described later. It is stipulated that the wireless communication unit with better communication quality should be attached preferentially.

In FIG. 23, a new wireless communication unit 1 (A) is approaching toward the leading wireless communication unit 1 (B). When the relay wireless communication unit 9 enters the range of the eNodeB 4 of the wireless communication unit 1 (B), the relay wireless communication unit 9 outputs an attach request to the eNodeB 4 of the wireless communication unit 1 (B). In the following, the attachment sequence described in FIG. 14 is executed, and an inter-unit wireless bearer 55 (A) is constructed between the wireless communication unit 1 (A) and the wireless communication unit 1 (B) as in the state A2. Then, the wireless communication unit 1 (A) is incorporated into the wireless network system. For example, in the state A2, the wireless communication unit 1 (A) has three new wireless communication units 1 (B) to 1 (two in the wireless base station unit 4 and one in the relay wireless communication unit 9). Regarding D), two new wireless communication units (one for the wireless base station section 4 and one for the relay wireless communication section 9) can be connected.

In the state B1 of FIG. 24, three wireless communication units 1 (A) to 1 (C) are connected by inter-unit wireless bearers 55 (A) to 55 (B), and the terminal wireless communication unit 1 (C) is connected. ), A new wireless communication unit 1 (D) is approaching. One wireless communication unit 1 (B) is already connected to the wireless base station unit 4 of the wireless communication unit 1 (C), and another new wireless communication unit can be connected. Then, when the relay wireless communication unit 9 of the approaching wireless communication unit 1 (D) enters the range of the wireless base station unit 4 of the approaching wireless communication unit 1 (C), the relay of the wireless communication unit 1 (D) is relayed. The wireless communication unit 9 transmits the attach request to the eNodeB 4 of the wireless communication unit 1 (C). In the following, the attachment sequence already described in FIG. 14 is executed, and as shown in the state B2 of FIG. 25, the inter-unit wireless bearer 55 (inter-unit wireless bearer 55) is located between the wireless communication unit 1 (D) and the wireless communication unit 1 (C). C1) is constructed, and the wireless communication unit 1 (D) is incorporated into the wireless network system in a branched manner. Further, similarly, the unconnected one (A2) of the relay wireless communication unit 9 of the wireless communication unit 1 (A) is attached to the wireless base station unit 4 of the wireless communication unit 1 (D), whereby the unit-to-unit wireless bearer 55 ( C2) is constructed, and the three wireless communication units 1 (A) to 1 (D) form a ring-shaped wireless communication net. FIG. 25 also shows a situation in which the wireless communication unit 1 (C) is attached to yet another wireless communication unit 1 (E).

For example, in FIG. 23, the newly added wireless communication unit is connected to the head of the constructed wireless communication network system, that is, the wireless communication unit forming the edge of the network (reference numeral 1 (A) in FIG. 23). The embodiment to be performed is shown. This method has an advantage that the addition of the wireless communication unit does not affect the connection order of the wireless communication units in the existing network and is simple. However, since the wireless communication unit to be added is attached and connected only when it approaches the wireless communication unit constituting the edge, there is a drawback that the flexibility for new addition of the wireless communication unit is somewhat poor. However, if a plurality of relay wireless communication units 9 can be independently attached to the radio base station unit 4 of another wireless communication unit 1, some relay wireless communication units 9 are already occupied by the attachment. As long as there is space in the other relay wireless communication unit 9, the unit can be attached to another wireless communication unit, and the connection topology can be changed extremely easily as the number of wireless communication units increases. On the other hand, since a plurality of wireless communication units (relay wireless communication units) that can be attached to and connected to the wireless base station unit 4 are allowed, the degree of freedom in changing the connection topology as the number of wireless communication units increases. Is increasing further.

On the other hand, the relay wireless communication unit is a wireless communication unit different from the upstream unit, and when there is a switching candidate unit capable of wireless connection with higher quality than the upstream unit, the switching candidate unit is used as a new upstream unit. It can also be configured to switch connections to. In FIG. 26, as the simplest case, the wireless communication unit 1 (C) located in the middle of the wireless communication network system composed of the plurality of wireless communication units 1 (A) to 1 (D), as in the state C1, Residual radio when separated by movement as in state C2 and separated from the network system as in state C3 (or when communication becomes impossible due to a failure or the like: this can also be said to be a kind of "disengagement") It shows the reconnection process of communication units 1 (A), 1 (B), 1 (D).

When the wireless communication unit 1 (C) is detached as described above, the communication quality between the upstream unit (wireless communication unit 1 (D) in FIG. 26) and the wireless communication unit 1 (C) deteriorates. The connection of the wireless bearer 55 (C) between units is disconnected. As a result, the wireless network system has two network clusters CR1 and CR2 having two wireless communication units 1 (B) and 1 (D) connected to the separated wireless communication unit 1 (C) as new edges. Disassemble into. Further, the wireless communication unit 1 (D) once isolated due to the disconnection becomes a switching candidate unit when viewed from the remaining wireless communication unit 1 (B) closest to the wireless communication unit 1 (D). In this case, as in the state C3, the wireless communication unit 1 (B) forming the edge of one network cluster CR1 requests the wireless communication unit 1 (D) forming the edge of the other network cluster CR2 to attach. A new inter-unit wireless bearer 55 (B') is constructed between the wireless communication unit 1 (B) and the wireless communication unit 1 (D) as in the state C4, and the two network clusters CR1 and CR2 are reconnected. Complete.

FIG. 26 shows a simple case in which the switching candidate unit generated by the withdrawal of the wireless communication unit 1 (C) is only one wireless communication unit 1 (B), but in reality, the remaining wireless communication unit 1 The movement of (A), 1 (B), and 1 (D) may cause a plurality of switching candidate units as seen from the wireless communication units forming the edge of, for example, the network clusters CR1 and CR2. Further, when another wireless communication unit outside the network approaches the wireless communication unit in the middle of the wireless communication network system, two or more wireless communication units located at the approach destination become switching candidate units. There is also.

Here, in order to change the connection of the wireless base station unit to which the relay wireless communication unit is connected to the wireless base station unit of another wireless communication unit, the wireless bearer between units that has already been constructed is temporarily disconnected, and the change destination In some cases, it may be necessary to reconstruct a new inter-unit wireless bearer between the wireless base station and the wireless communication unit. At this time, when another wireless communication unit outside the network approaches the wireless communication unit whose number of connected downstream units has reached the upper limit (2 in this embodiment), the wireless bearer between the units is disconnected. Depending on the situation, if the wireless communication unit on the upstream side can be forcibly executed by the instruction of the EPC function unit, the connection topology between the wireless communication units can be optimized by reconstructing the wireless bearer between units. It can be easily planned. Specifically, the EPC function unit instructs the radio base station unit to temporarily and forcibly disconnect the downstream unit radio bearer from the downstream unit (Fig. 3: Function of network adjustment program 305h), and wirelessly. Upon receiving an instruction, the base station section controls the disconnection of the wireless bearer between downstream units. In this case, the upstream unit connection switching control unit is the old upstream unit, which is a wireless communication unit connected as an upstream unit by the upstream unit wireless bearer as the upstream unit wireless bearer is disconnected, and the switching candidate unit. The communication quality is evaluated for each of the above, and the wireless communication unit to be connected as a new upstream unit is determined based on the result of the communication quality evaluation (function of the upstream unit connection switching control program 905b).

An example thereof is shown in FIGS. 27 to 29. In the state D1 of FIG. 27, the five wireless communication units 1 (A), 1 (B), 1 (C), 1 (E), and 1 (F) are inter-unit wireless bearers 55 (A) and 55 (B). , 55 (D), 55 (E), and a new wireless communication unit 1 (D) is approaching toward the middle of the wireless communication unit 1 (B) and the wireless communication unit 1 (C). .. The two relay wireless communication units 9 (B1, B2) of the wireless communication unit 1 (B) are attached to the wireless communication units 1 (E) and 1 (C), and the wireless base of the wireless communication unit 1 (B). The number of downstream units connected to the local area 4 has also reached the upper limit. Therefore, it is impossible for the wireless communication unit 1 (D) to connect to the wireless communication unit 1 (B) and the wireless communication unit 1 (C) as it is. In this situation, for example, the wireless bearer forced disconnection indicator between the downstream units of the wireless communication unit 1 (C) to which the two downstream units 1 (B) and 1 (F), which are already the upper limit, are connected, is being connected. The wireless communication unit 1 (D) that acquires the downstream unit distance information reflecting the distances dc1 and dc2 from the downstream units 1 (B) and 1 (F) (downstream unit distance information acquisition unit), and further serves as a switching candidate unit. Acquires switching candidate unit distance information reflecting the distance d1 to and from (switching candidate unit distance information acquisition unit). In the state D1, d1> dc1 and dc2.

Then, as in the state D2 of FIG. 28, the distance d1 with the switching candidate unit reflected in the acquired switching candidate unit distance information is the distance with the downstream unit reflected in the acquired downstream unit distance information (for example,). (Distance from downstream unit 1 (B)) When it becomes smaller than dc1, the EPC function unit 3 of the wireless communication unit 1 (C) has a wireless bearer (55 (B)) between downstream units with respect to the radio base station unit 4. Is instructed to temporarily and forcibly disconnect. As a result, when the switching candidate unit (1 (D)) approaches so as to be closer than the downstream unit (1 (C)) that is already connected as in the state D3, the wireless bearer between the downstream units is determined by the above distance determination. Is forcibly disconnected, and the inter-unit radio bearer 55 (B') is reconstructed so that a new connection with the closer switching candidate unit (1 (D)) is generated as shown in the state D4 of FIG. The communication quality and throughput of the wireless can be significantly improved.

Various acquisition methods for the downstream unit distance information and the switching candidate unit distance information can be selected. For example, the simplest method is the current position acquisition unit that acquires the current position of the wireless communication unit in the wireless communication unit. The downstream unit distance information acquisition unit and the switching candidate unit distance information acquisition unit acquire their respective current positions from the downstream unit and the switching candidate unit, and the distance and switching with the downstream unit based on the information of their current positions. A method of calculating the distance to each candidate unit can be exemplified. In the present embodiment, as shown in FIG. 3, GPS 413 (connected to the bus 405) forming the current position acquisition unit is provided in the radio base station unit 4 of each wireless communication unit 1, for example, wireless communication in FIG. 28. The unit 1 (C) can acquire the position information of the downstream unit 1 (B) as GPS information via the downstream unit radio bearer (55 (B)). Further, regarding the position information of the switching candidate unit (1 (D)) in which the inter-unit wireless bearer is not constructed, GPS is provided in FIG. 3 via the external network 60 connected to the router 8 via the satellite communication line 61. It can be obtained as information.

FIG. 33 shows an example of the flow of the wireless bearer forced disconnection process between downstream units in this case by the network adjustment program 305h described above. In FIG. 28 (state D2), it is the EPC function unit 3 of the wireless communication unit 1 (D) that performs the processing. The C200 acquires its own position information from GPS 413 (FIG. 3). This location information is uploaded to the external network 60 (FIG. 3) so that other wireless communication units can use it for distance calculation. In C201, it is determined whether or not the number of downstream units being attached / connected has reached the upper limit (for example, 2 in this embodiment). If the upper limit is reached, the process proceeds to C202, and the position information of the connected downstream units 1 (B) (FIG. 28) is acquired via the inter-unit wireless bearer 55 (B), and the above-mentioned own position is acquired. The distance dc is calculated based on the information.

Then, in C203, the position information of the peripheral switching candidate unit (wireless communication unit 1 (D) in FIG. 3) is acquired via the external network 60 (FIG. 3). In C204, the distance to each switching candidate unit is calculated, and the closest one is specified as d1. Then, at C205, when d1 <dc, the process proceeds to C206, and the inter-unit wireless bearer 55 (B) with the connected downstream unit 1 (B) (FIG. 28) is temporarily disconnected (FIG. 28: state). D2). Further, in C205, if d1 <dc is not satisfied, C206 is skipped. On the other hand, in C201, if the number of downstream units being attached / connected does not reach the upper limit, a new bearer between downstream units can be newly constructed, so that the forced disconnection process is unnecessary and jumps to C207. If the process is not completed at C207, the process returns to C200 and the following process is repeated.

When the inter-unit radio bearer is disconnected as described above as in the state D2 of FIG. 28, one (B2) of the relay radio communication unit 9 of the old downstream unit 1 (B) edged by this is an upstream unit. The old upstream unit 1 which is a wireless communication unit connected as an upstream unit by the wireless bearer 55 (B) between upstream units as in state D3 by the connection switching control program 905b (FIG. 3: upstream unit connection switching control unit). Communication quality evaluation is performed for each of (C) and the switching candidate unit 1 (D), and a process of determining a wireless communication unit to be connected as a new upstream unit is performed based on the result of the communication quality evaluation. This makes it possible to further improve the communication quality with the wireless communication unit after reconnection and the throughput of communication between the wireless communication units.

In the present embodiment, a CQI reference signal is received from each wireless communication unit 1 (C) and 1 (D), CQI information (FIG. 32) is generated using the CQI reference signal, and the content of the CQI information is used. Communication quality is evaluated. In the case of LTE terminals (UE and relay wireless communication unit), the CQI information measurement / generation processing function is indispensable for the resource block scheduling algorithm as described above, and is incorporated as a standard specification in the 3GPP protocol. There is an advantage that this can be diverted. However, in the LTE protocol, the CQI measurement is performed after the terminal is attached to the radio base station, and in order to apply it to the present invention, the CQI measurement is performed before the attachment, which is outside the standard protocol. It is necessary to devise the processing of.

FIG. 34 shows an example of the flow of the upstream unit connection switching control process. In FIG. 28 (state D3), it is the relay wireless communication unit 9 of the wireless communication unit 1 (B) that constitutes the old downstream unit that performs the processing. The wireless base station units 4 of the wireless communication units 1 (C) and 1 (D), which are connection candidates, output notification information for accepting attachments of the UE 5 and the relay wireless communication unit 9, respectively, in accordance with the LTE protocol. Then, in the present embodiment, as a process outside the standard protocol, a reference signal for CQI measurement is transmitted in a form following this broadcast information. In the resource block matrix of FIG. 10, this reference signal uses a subcarrier of a predetermined frequency at a specific symbol (for example, symbols “0” and “4”) in each slot on the time axis. It has been inserted. Therefore, if the symbol number in the slot for acquiring the reference signal and the frequency subcarrier specific information are incorporated in the broadcast information, the relay wireless communication unit 9 of the wireless communication unit 1 (B) can be used. Can be read to perform reception setting processing of the reference signal for CQI measurement.

Returning to FIG. 34, in C102, it is confirmed whether or not the CQI reference signal is received. If it is receiving, the process proceeds to C103, and it is determined whether or not the CQI reference signal is received from a plurality of wireless communication units. If received, proceed to C104 and perform CQI measurement for each CQI reference signal. Then, the process proceeds to C105, and as shown in the state D4 of FIG. 29, in the wireless communication unit having the best communication quality indicated by the measured CQI among the plurality of units (1 (C), 1 (D)), for example, FIG. 29. For example, by requesting attachment to the wireless communication unit 1 (D) that has the best coding rate and frequency utilization efficiency reflected in the CQI information (see FIG. 32) as a result of being closest to the wireless communication unit 1 (B). , An inter-unit wireless bearer 55 (B') is constructed with the wireless communication unit 1 (D). On the other hand, in C103, when the CQI reference signal is not received from a plurality of wireless communication units, that is, when it is received from only one wireless communication unit, the process proceeds to C106, and the unit is sent to the unit regardless of the CQI measurement result. Make an attach request. If it does not end at C107, it returns to C101 and repeats the following processing.

Although the embodiments of the present invention have been described above, the present invention is merely an example, and the present invention is not limited thereto. For example, the content of the forced disconnection process of the wireless bearer between downstream units is not limited to the above, and the EPC function unit of the upstream unit periodically outputs an instruction to disconnect the wireless bearer between downstream units at predetermined time intervals. It can also be configured as follows. The radio base station disconnects the downstream unit radio bearer periodically (for example, once an hour to once a year, preferably once every three hours to three months so that the effect on communication quality is small). The processing flow after the downstream unit radio bearer is disconnected is the same as that described above.

Further, in the wireless communication units 1'(A) to 1'(C) shown in FIG. 36, a plurality of wireless base station units 4 (X) and 4 (Y) capable of independently constructing the inter-unit wireless bearer 55 are provided. It is provided. In FIG. 36, the wireless communication unit 1'(A) is used as the upstream unit, and the wireless communication unit 1'(B) is connected to the wireless base station unit 4 (X) as the downstream unit. (X) is constructed, and the wireless communication unit 1'(C) is connected to the radio base station unit 4 (Y) in the form of constructing an inter-unit wireless bearer 55 (Y). In this case, the inter-unit radio bearer 55 (X) and the inter-unit radio bearer 55 (Y) can be set to different frequency channels. As a result, the communication capacity (throughput) between the inter-unit wireless bearer 55 (X) and the inter-unit wireless bearer 55 (Y) can be significantly increased.

1 (A), 1 (B) Wireless communication unit WS (A), WS (B) Large vessel 2 MME
3 EPC function unit 301 CPU
302 RAM
303 mask ROM
304A Upstream communication interface 304B Downstream communication interface 305 Flash memory 305a Communication firmware 305b MME entity 305c S-GW entity 305d P-GW entity 305e Transfer table 305ert Routing table 305f Transfer table update program 305g Channel map 306 Bus 21 Secondary battery module 22 Power supply circuit unit 23 Portable housing 30, 31 Communication bus 4 Radio base station unit 401 CPU
402 RAM
403 mask ROM
404 Communication interface 405 Flash memory 405a Communication firmware 406 Bus 412 Wireless communication unit 5 UE (mobile terminal)
6 S-GW
7 P-GW
8 Router 9 Relay wireless communication unit 901 CPU
902 RAM
903 mask ROM
905 Flash memory 905a Communication firmware 906 Bus 912 Wireless communication unit 50 (A), 50 (B) Communication area 55 Unit-to-unit wireless bearer 57 Wireless bearer for terminals

Claims (20)

A wireless communication unit that is configured to be mounted on a mobile body and for performing wireless network communication with a mobile terminal.
A wireless base station unit to which the mobile terminal can be connected via a wireless bearer for terminals,
An EPC (Evolved Packet Core) function unit that is wiredly connected to the radio base station unit and functions as an upper network control unit for the radio base station unit.
Along with being wiredly connected to the EPC function unit, a wireless base station unit (hereinafter referred to as an upstream wireless base station unit) of an upstream unit, which is another first wireless communication unit, and a wireless bearer between units on the upstream side (hereinafter, upstream unit). It is equipped with multiple relay wireless communication units that can be connected via a wireless bearer).
The radio base station unit is a relay radio communication unit (hereinafter referred to as a downstream relay radio communication unit) of a downstream unit which is another second radio communication unit and a unit-to-unit radio bearer on the downstream side (hereinafter referred to as a downstream unit radio bearer). ) Can be connected via
The EPC function unit transmits a downstream unit-to-unit radio bearer setting request to the radio base station unit, while the radio base station unit receives the downstream unit-to-unit radio bearer setting request and together with the downstream relay radio communication unit, the downstream unit-to-unit radio. It builds a bearer,
The EPC function unit transmits a terminal radio bearer setting request to the radio base station unit, while the radio base station unit receives the terminal radio bearer setting request and constructs the terminal radio bearer together with the mobile terminal. Yes,
The plurality of relay radio communication units receive the upstream unit-to-unit radio bearer setting request issued by the EPC function unit of the upstream unit (hereinafter referred to as the upstream EPC function unit), and receive the upstream unit-to-unit radio bearer setting request. A radio communication unit characterized in that a radio bearer between upstream units is individually constructed together with the upstream radio base station unit. The wireless communication unit according to claim 1, wherein the plurality of relay wireless communication units can individually construct the upstream unit-to-upstream wireless bearer between the relay wireless communication units and the upstream radio base station units that are different from each other. When the plurality of relay radio communication units detect a candidate for an upstream unit to be a new connection destination in a state where the upstream unit is not connected, the inter-upstream unit radio bearer is used with respect to the candidate radio base station unit of the upstream unit. Upstream unit-to-unit radio bearer construction control that receives an inter-upstream unit radio bearer setting request from the upstream unit candidate and controls to construct the upstream unit-to-unit radio bearer by transmitting an attach request for constructing the upstream unit. The wireless communication unit according to claim 1 or 2, each comprising a unit. The method according to any one of claims 1 to 3, wherein the radio base station unit is such that the relay radio communication unit of the plurality of downstream units can be simultaneously connected to each other via the individual downstream unit radio bearers. Wireless communication unit. When the radio base station unit receives an attach request from a candidate for a newly connected downstream unit in a state where the number of connected downstream units is 1 or less, the radio base station unit notifies the EPC function unit of the attach request. The downstream unit wireless bearer construction control unit that receives the terminal wireless bearer setting request from the EPC function unit and controls the construction of the downstream unit wireless bearer with the downstream unit candidate. The wireless communication unit according to claim 4. The wireless communication unit according to any one of claims 1 to 3, wherein a plurality of the wireless base station units are connected to one EPC control unit, and each of the relay wireless communication units of the downstream unit can be connected. .. 6. Claim 6 in which the relay radio communication units of the downstream units are connected to the radio base station units connected to the EPC control unit by a radio bearer between the downstream units, which are set on different frequency channels. The wireless communication unit described. The relay wireless communication unit is a wireless communication unit different from the upstream unit, and when there is a switching candidate unit capable of wireless connection with higher quality than the upstream unit, the switching candidate is used as a new upstream unit. The wireless communication unit according to any one of claims 1 to 7, further comprising an upstream unit connection switching control unit for switching the connection to the unit. The wireless communication unit according to claim 8, wherein the upstream unit connection switching control unit switches the connection to the switching candidate unit when the connection with the upstream unit is disconnected due to a deterioration in communication quality with the upstream unit. .. The EPC function unit includes a downstream unit radio bearer forced disconnection instruction unit that instructs the radio base station unit to temporarily and forcibly disconnect the downstream unit radio bearer from the downstream unit. The radio base station unit includes a downstream unit radio bearer disconnection control unit that controls disconnection of the downstream unit radio bearer in response to the instruction.
The upstream unit connection switching control unit has the old upstream unit, which is a wireless communication unit connected as the upstream unit by the upstream unit wireless bearer, and the switching candidate as the upstream unit wireless bearer is disconnected. The wireless communication unit according to claim 8 or 9, wherein a communication quality evaluation is performed for each of the units, and a wireless communication unit to be connected as a new upstream unit is determined based on the result of the communication quality evaluation. The upstream unit connection switching control unit receives a CQI (Channel Quality Indicator) reference signal from each of the wireless communication units, generates CQI information using the CQI reference signal, and communicates based on the content of the CQI information. The wireless communication unit according to claim 10, wherein quality evaluation is performed. The EPC function unit relates to the relay radio communication unit of the plurality of mobile terminals and other radio communication units connected to the radio base station via the terminal radio bearer in the communication area of the radio base station unit. , The mobile terminal to be the destination of the IP packet transferred from the wireless base station unit is provided with the connected terminal registration unit for registering the terminal specific information of the connected mobile terminal, and the registration contents of the connected terminal registration unit. When the mobile terminal to be the transmission destination indicates a mobile terminal corresponding to any of the terminal specific information registered in the connected terminal registration unit, the IP packet is sent to the mobile terminal by the wireless. When the mobile terminal to be the transmission destination indicates a mobile terminal that is not registered in the connected terminal registration unit, the IP packet is sent to the relay wireless communication unit and the wireless base. The wireless communication unit according to any one of claims 1 to 11, which controls transfer from at least one of the local parts to a transmission destination outside the wireless communication unit. A wireless communication unit that is configured to be mounted on a mobile body and for performing wireless network communication with a mobile terminal.
A wireless base station unit to which the mobile terminal can be connected via a wireless bearer for terminals,
An EPC (Evolved Packet Core) function unit that is wiredly connected to the radio base station unit and functions as an upper network control unit for the radio base station unit.
Along with being wiredly connected to the EPC function unit, a wireless base station unit (hereinafter referred to as an upstream wireless base station unit) of an upstream unit, which is another first wireless communication unit, and a wireless bearer between units on the upstream side (hereinafter, upstream unit). It is equipped with multiple relay wireless communication units that can be connected via a wireless bearer).
The radio base station unit is a relay radio communication unit (hereinafter referred to as a downstream relay radio communication unit) of a downstream unit which is another second radio communication unit and a unit-to-unit radio bearer on the downstream side (hereinafter referred to as a downstream unit radio bearer). ) Can be connected via
The EPC function unit transmits a downstream unit-to-unit radio bearer setting request to the radio base station unit, while the radio base station unit receives the downstream unit-to-unit radio bearer setting request and together with the downstream relay radio communication unit the downstream unit-to-unit radio. The bearer is constructed, and the EPC function unit transmits a terminal wireless bearer setting request to the radio base station unit, while the radio base station unit receives the terminal radio bearer setting request and the terminal together with the mobile terminal. To build a wireless bearer for
The plurality of relay radio communication units receive the upstream unit-to-unit radio bearer setting request issued by the EPC function unit (hereinafter referred to as the upstream EPC function unit) of the upstream unit, and receive the upstream unit-to-unit radio bearer setting request. It consists of a group of wireless communication units in which a plurality of wireless communication units individually configured to individually construct the upstream unit-to-upstream wireless bearer together with the upstream radio base station unit are arranged.
The wireless communication unit group is connected by the inter-unit wireless bearer in a positional relationship in which base station cells of a pair of wireless communication units adjacent to each other partially overlap each other.
A mobile terminal connected to one of the wireless communication unit pairs and a mobile terminal connected to the other wireless communication unit pair transmit and receive IP packets via the unit-to-unit wireless bearer connecting the wireless communication unit pair and the wireless communication unit pair. A wireless network system characterized by performing. 13. The wireless network system according to claim 13, wherein in at least one of the wireless communication units, a plurality of relay wireless communication units are connected to the wireless base station units of the upstream units, which are different from each other, by an inter-unit wireless bearer. In the radio base station unit, the relay radio communication unit of the plurality of downstream units can be simultaneously connected via individual downstream unit radio bearers, and in at least one of the radio communication units, the radio base station unit The wireless network system according to claim 14, wherein a plurality of the downstream units different from each other are connected by the inter-unit wireless bearer. The wireless network system according to claim 15, wherein a plurality of the wireless communication units are connected in a mesh pattern by the wireless bearers between the units. Each of the EPC functional units of the plurality of wireless communication units connected by the inter-unit wireless bearer is connected to the wireless base station via the terminal wireless bearer within the communication area of the wireless base station unit. The relay wireless communication unit of the mobile terminal and the other wireless communication unit is provided with a connected terminal registration unit for registering terminal specific information of the connected mobile terminal, and an IP packet transferred from the wireless base station unit. The mobile terminal to be the transmission destination is collated with the registered contents of the connected terminal registration unit, and the mobile terminal to be the transmission destination corresponds to any of the terminal identification information registered in the connected terminal registration unit. When indicating a terminal, the IP packet is transferred to the mobile terminal in a form of being folded back at the wireless base station unit, while the mobile terminal to be the transmission destination is not registered in the connected terminal registration unit. When indicated, according to any one of claims 13 to 16, which controls the transfer of the IP packet from at least one of the relay radio communication unit and the radio base station unit to a destination outside the radio communication unit. The wireless network system described. The EPC function unit creates a transfer table of the IP packet based on the terminal identification information of the relay wireless communication unit shared, and controls the transfer of the IP packet with reference to the transfer table. A system having a transfer table update control unit that updates the contents of the transfer table according to the change contents when at least one of the number of the wireless communication units and the connection order included in the wireless network system is changed. The wireless network system according to claim 17. In each of the wireless communication units, the forwarding table includes a connected terminal registration unit in which the addresses of connected mobile terminals are registered in a list, and a wireless communication unit that is the final transfer destination of received packets. The EPC function unit includes the number of the wireless communication units and the connection order, and includes a routing table in which the address of is stored in association with the address of the wireless communication unit to be the next transfer destination of the received packet. The wireless network system according to claim 18, further comprising a routing table changing unit that changes the contents of the routing table according to the changed contents when at least one of the above is changed. A wireless communication unit that is the final transfer destination of the packet is a destination node, a plurality of the wireless communication units that reach the destination node are relay nodes, and the next transfer destination when the packet is transmitted to the destination node. With the wireless communication unit as the next hopping node, each of the wireless communication units has the address of the next hopping node corresponding to the destination node of the routing table so that the route is optimized in the direction in which the number of relay nodes decreases. 19. The wireless network system according to claim 19, which has a routing table update unit for updating and setting.

Images