JP2016076900A - Radio network integration system and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio network integration system and a radio network integration method, capable of highly reliable communication with a reduced network implementation cost.SOLUTION: Each base station 21 in a plurality of radio communication network systems 11 acquires a reference frequency and an absolute time which are common to all base stations 21. A network control unit 13 allocates a radio resource to each radio communication network system 11 in a time domain and a frequency domain, to transmit the allocation information thereof to each base station 21 of each radio communication network system 11 through an inter-base station communication network 12, as information based on the reference frequency and the absolute time. According to the allocation information transmitted from the network control unit 13, each radio communication network system 11 performs radio communication between each base station 21 and each terminal 22.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wireless network integration system and a wireless network integration method.

  In recent years, with the development of wireless and wired communication technologies, the amount of information flowing through networks has increased rapidly. According to various statistics, the increase amount is about 1.5 to 2 times every year, and it is expected that about 10 to 15 years later, the communication capacity will be about 1000 times that of 2010.

  On the other hand, next-generation communication networks are required to have extremely high reliability as infrastructure infrastructure indispensable to society. In societies that assume that everything is connected to the network, disruption of network access can cause significant social disruption. In addition, in order to ensure emergency communication means to accurately communicate your location and situation in the event of a major natural disaster, etc., a high-availability network that guarantees minimum network access in any situation Realization is essential.

  Heterogeneous wireless integrated network (heterogeneous network) combining multiple communication systems with different properties is an effective means to realize the above two requirements, large capacity (= high efficiency) and high reliability. It is done. This is a network designed to overlap transmission / reception ranges of a plurality of radio base stations so that a single mobile station (terminal) can be covered by a plurality of radio systems. According to this concept, even if one system stops due to some factor, the terminal can continue communication with another system.

  In addition, in a heterogeneous network, when overlapping transmission / reception ranges of a plurality of radio base stations, a technique of combining base stations having different cell radii is effective. That is, a macro base station that can cover a wide range with a single base station overlaps a small base station that covers only a short distance. A small base station can reuse the same frequency resource in a short cycle, and since the communication distance is short, the transmission power can be reduced, and by suppressing interference power, the frequency utilization efficiency can be kept high. Is possible. On the other hand, since the macro base station covers a large area with high power, it exerts its strength in securing a transmission / reception range including indoor terminals and high-speed mobile terminals. In this way, by combining radio stations with different properties. Large capacity = frequency utilization efficiency can be improved.

  However, in order to produce an effect of integrating a plurality of systems having different properties, a close linking operation is required between the systems. For this purpose, a very complicated control mechanism is required on the network side, and there is a concern that the construction and operation costs of the entire network increase.

  A system configuration for realizing a heterogeneous network is being studied by 3GPP (Third Generation Partnership Project) as a cooperative multipoint transmission / reception method (CoMP) or small cell enhancement (SCE). For example, as an example of CoMP system configuration, multiple small base stations (RRE: Remote Radio Equipment) that operate together are connected to a single macro base station (central eNB) using dedicated optical fibers, and all RRE signals There is disclosed a technique that solves inter-station synchronization such as transmission timing adjustment and sharing of control information by performing processing centrally in one macro base station, thereby realizing inter-station cooperation (for example, Patent Document 1). In addition, in the 3GPP system, all radio stations adopt the same communication method such as LTE-Advanced, and because of the use of license bands, the highest priority is on improving frequency utilization efficiency. It is considered that such a configuration is selected.

  On the other hand, in a heterogeneous system integrated network that combines WRAN (for example, IEEE802.22) and WLAN (for example, IEEE802.11n), close inter-station cooperation as in Non-Patent Document 1 is difficult. These systems are based on the concept of distributed network control, and use a simple control method in which a signal of the local station is transmitted after confirming a free state of a line by carrier sense. For this reason, there is almost no concept of inter-station synchronization, making the linkage operation difficult.

  The WRAN base station with a wide communication area controls the use channel of the WLAN to avoid interference, and the WRAN transmission / reception is temporarily stopped, and the WLAN communication is performed during that time. A method of performing is disclosed (for example, see Patent Document 1). According to this method, since a single frequency resource can be shared between a plurality of WRAN systems and WLAN systems without causing interference, cooperative control can be realized even in a distributed network.

Taoka, Nagata, Takeda, Takashima, Yo, Sasame, "MIMO and inter-cell cooperative transmission technology in LTE-Advanced", NTT DOCOMO Technical Journal, July 2010, Vol.18, No.2, p.22-30

JP 2013-187604 A

  In a heterogeneous network, in order to coordinately control a plurality of wireless systems, how to ensure synchronization between stations becomes a big problem. Although the 3GPP type centralized control system described in Non-Patent Document 1 can achieve reliable inter-station synchronization, it is necessary to install dedicated optical fibers for all the RREs that are subject to cooperative control. There was a problem that the cost increased. In addition, in order to maximize frequency utilization efficiency, it is extremely complicated to estimate the optimal RRE combination for a specific terminal and arrange time and frequency so as to suppress the influence of interference among multiple terminals. There was a problem that a costly network construction cost would increase due to the necessity of a scheduler.

  On the other hand, as described in Patent Document 1, the method of performing mutual interference control (resource allocation) while retaining the concept of a distributed network such as WRAN and WLAN achieves both moderate performance improvement and cost reduction. Although there is a possibility, there is a problem of how to secure a synchronization mechanism for a system that does not originally have an inter-station synchronization function. One possible method is to connect the stations to be linked with a dedicated optical fiber (or coaxial cable) with guaranteed delay to ensure time / frequency synchronization. However, this method requires that a dedicated optical fiber be installed between WRAN base stations and between WLAN access points (APs), and as with the above-described centralized control method, the cost of network construction increases. There is. This method also takes away the advantages of a WLAN that can be easily constructed.

  As another method, it is possible to use a network listening method using a beacon of a wide area station (for example, WRAN or WMAN), but it is necessary to install an AP at a point where communication from the wide area station can be surely received. However, there is a problem in that communication becomes unstable due to restrictions on the installation near the cell edge where interference between wide-area stations becomes a problem. Also, especially in the case of a wireless system using the ISM band, carrier sense for interference suppression is required prior to transmission, so transmission from a wide area station is not necessarily guaranteed at the intended timing. There is also a problem of causing great uncertainty in inter-station timing synchronization. Note that this method is a method in which control is performed using a relative value from the beacon timing of the wide area stations, and there remains a problem of how to synchronize the timings of the wide area stations.

  The present invention has been made paying attention to such problems, and an object of the present invention is to provide a wireless network integration system and a wireless network integration method capable of reducing network construction costs and performing communication with high reliability. And

  In order to achieve the above object, an integrated wireless network system according to the present invention includes a plurality of wireless units each having one or a plurality of base stations and a plurality of terminals provided so as to be able to perform wireless communication with the base stations. A wireless network integration system for integrating communication network systems, comprising: an inter-base station communication network connected to the base station of each radio communication network system; and a network control unit connected to the inter-base station communication network. The base station is provided so as to be able to acquire a reference frequency and an absolute time common to all base stations, and the network control unit allocates radio resources to each radio communication network system in a time domain and / or a frequency domain. And assigning the allocation information as information based on the reference frequency and the absolute time. Each wireless communication network system is configured to transmit to each base station of each wireless communication network system via a network, and each base station and each terminal according to the allocation information transmitted by the network control unit It is comprised so that wireless communication may be performed between.

  A wireless network integration method according to the present invention is for integrating a plurality of wireless communication network systems each having one or a plurality of base stations and a plurality of terminals provided so as to be able to perform wireless communication with the base stations. A wireless network integration method, comprising: a communication network between base stations connected to the base station of each wireless communication network system; and a network control unit connected to the communication network between base stations, And acquiring a reference frequency and an absolute time common to all base stations, and the network control unit allocates radio resources to each radio communication network system in the time domain and / or frequency domain, and assigns the allocation information to the reference As information based on the frequency and the absolute time, each wireless communication network system via the inter-base station communication network is used. And of transmitting to the base station, each wireless communication network system, according to the allocation information transmitted by the network controller, and performs wireless communication between a respective said base station and each terminal.

  In the wireless network integrated system according to the present invention, at least one wireless communication network system has a communication area partially or entirely overlapping with a communication area of at least one other wireless communication network system, and the communication areas overlap. It is preferable that each terminal of the wireless communication network system can be used in each wireless communication network system as long as the communication areas overlap. The wireless network integration method according to the present invention is a method implemented by the wireless network integration system according to the present invention, and can obtain the same operations and effects as those of the wireless network integration system according to the present invention.

  In the wireless network integration system and the wireless network integration method according to the present invention, each base station acquires a reference frequency and an absolute time common to all base stations, so that all base stations synchronize time and frequency. Can do. Thus, as time and frequency allocation information, it is only necessary to send information based on the reference frequency and the absolute time to the base station of each wireless communication network system via the inter-base station communication network. There is no need to send a timing pulse or a clock signal for frequency synchronization. For this reason, an inexpensive IP network for non-real-time communication can be used as an inter-base station communication network instead of an expensive dedicated line for real-time communication for supplying timing pulses and clock signals. Can be reduced.

  In the wireless network integration system and the wireless network integration method according to the present invention, each wireless communication network system performs wireless communication between each base station and each terminal in the time domain and / or frequency domain assigned by the network control unit. Therefore, even when the communication areas of the wireless communication network systems overlap, interference between the wireless communication network systems can be prevented. In addition, since all base stations synchronize time and frequency, it is possible to prevent the occurrence of timing synchronization uncertainty. For this reason, communication between each base station and each terminal can be performed with high reliability. Moreover, frequency utilization efficiency can be improved and it can contribute to construction of a large capacity communication system.

  In the wireless network integration system and the wireless network integration method according to the present invention, the wireless communication network system may be any network system that performs wireless communication, such as wide area cellular, WRAN, WLAN, WPAN, etc. It is. Base stations include not only wide-area cellular and WRAN base stations, but also WLAN access points, CSMA / CA hosts, and the like. The allocation information transmitted from the network control unit includes, for example, information on a time zone and / or a frequency channel that can be used in each wireless communication network system.

  In the wireless network integrated system according to the present invention, it is preferable that the base station can receive a positioning signal from a satellite and acquire the reference frequency and the absolute time based on the positioning signal. In this case, all base stations can synchronize time and frequency by means other than the network using satellite communication. As satellites, global navigation satellite systems (GNSS) such as GPS in the United States, GLONASS in Russia, CNSS in China, and QZSS (Quasi-Zenith Satellite System) in Japan can be used. Note that the base station may be able to acquire the information from information providing means other than the satellite as long as it can acquire the reference frequency and absolute time common to all the base stations.

  In the wireless network integrated system according to the present invention, a part of the communication network between base stations may be composed of a dedicated line or a wireless communication line. This includes, for example, a configuration in which a timing pulse is distributed by a dedicated line or a radio signal from a base station that can be synchronized with a positioning signal of a satellite to a base station that is invisible to surrounding satellites. Also in this case, the network construction cost can be reduced compared to the case where all the communication networks between base stations are dedicated lines.

  In the wireless network integrated system according to the present invention, each wireless communication network system is configured to perform wireless communication between the base station and each terminal by an access control method specific to each system according to the allocation information. It is preferable. In this case, it is possible to separate inter-system (inter-base station) resource allocation control for suppressing interference between radio communication network systems and scheduling / access control for terminals under the base station of each radio communication network system. it can. That is, it is possible to perform resource allocation control between radio communication network systems based on the allocation information of the network control unit, and perform scheduling / access control using an access control method unique to each radio communication network system.

  In particular, the access control of each terminal is required to follow fading fluctuation and the like, and severe delay limitation is imposed on the aggregation of information necessary for control of the transmission path state (CSI: Channel State Information) of each terminal. For example, in the 3GPP type centralized control method, RRE and frequency to be used can be determined in consideration of CSI, so that extremely high frequency utilization efficiency can be achieved, but a complicated control mechanism is required. In addition, sharing information necessary for CSI control via the backbone is almost equivalent to requesting a delay-guaranteed dedicated line, which increases network construction costs. In the wireless network integrated system according to the present invention, scheduler allocation can be performed by separating resource allocation between base stations that is control in units of several seconds and scheduling of terminals that are required to control in units of milliseconds. Therefore, it is possible to realize a moderate improvement in frequency utilization efficiency while reducing the network construction cost.

  In the wireless network integrated system according to the present invention, each terminal can measure communication quality information with a communicable base station, and the communication quality information can be communicated as probe information together with measurement position information at the time of measurement. The base station of each wireless communication network system is configured to transmit throughput-related information necessary for calculating its own throughput. Configured to transmit to the network control unit, the network control unit, based on the probe information transmitted from each terminal and the throughput-related information transmitted from each base station, each radio resource It may be configured to be assigned to a wireless communication network system.

  Further, in the wireless network integrated system according to the present invention, the base station of each wireless communication network system is configured to transmit throughput-related information necessary for calculating its own throughput to the network control unit, The network control unit transmits the radio resource to each radio communication based on the probe information including communication quality information of each base station at an arbitrary position obtained in advance and the throughput-related information transmitted from each base station. It may be configured to be assigned to a network system.

  When allocating radio resources based on these probe information and throughput-related information, a radio communication environment with good communication quality and low load can be allocated, and high-reliability and high-speed communication can be performed. . In addition, the line utilization rate can be increased. The throughput-related information includes, for example, the number of terminals that can be connected to each base station, the number of connected terminals, the average traffic volume, and the like.

  In these cases, the network control unit creates a communication quality database indicating the communication quality of each base station at an arbitrary position based on the probe information and the throughput-related information, and from the communication quality database, Based on the position of each terminal, a priority order of base stations with which each terminal can communicate is obtained, and for each terminal and each base station, a map including communication quality information and priority order information corresponding to each terminal and each base station The information may be edited, the radio resource may be allocated to each radio communication network system based on the map information, and the map information may be transmitted to the corresponding terminal and base station. In this case, even if the communication areas of the wireless communication network systems overlap, it is possible to select a base station of the wireless communication network system with better communication quality and lower load based on the location information of each terminal. In this case, the wireless communication system and wireless communication method disclosed in Japanese Patent Application No. 2013-250343 by the present inventors can be used.

  Further, in this case, the network control unit obtains base stations in a relationship of causing interference with each other from the communication quality database, and sets the radio resources to each radio communication so as to suppress interference between the base stations as much as possible. It may be assigned to a network system.

  In the wireless network integrated system according to the present invention, the network control unit creates one or a plurality of groups, with a plurality of wireless communication network systems having overlapping communication areas as one group, and belongs to each group. The wireless resource is configured to be assigned to each group and to a wireless communication network system that does not belong to any group so that the assigned time of each wireless communication network system partially or entirely overlaps, and belongs to any group Each terminal of the wireless communication network system can be used in each wireless communication network system belonging to the group as long as the communication areas of the group overlap, and the information for wireless communication is divided into a plurality of parts. Each information Based on the reliability and / or communication capacity of each wireless communication network system belonging to the group, it is allocated to each wireless communication network system, and in accordance with the allocation information transmitted by the network control unit, between the corresponding base stations And may be configured to perform wireless communication.

  When grouping the wireless communication network systems, the wireless communication network systems in the group are assigned to, for example, a data channel and a control channel on the basis of the reliability and communication capacity. Suitable and efficient communication can be performed.

  According to the present invention, it is possible to provide a wireless network integration system and a wireless network integration method that can reduce network construction costs and perform communication with high reliability.

1 is an overall configuration diagram showing a wireless network integration system according to a first embodiment of this invention. It is a block block diagram which shows the base station of the radio | wireless network integrated system of the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS (a) Whole structure figure which shows an example of the wireless network integrated system of the 1st Embodiment of this invention, (b) It is explanatory drawing of scheduling. It is a block block diagram which shows the terminal of a radio | wireless communications system. It is a block block diagram which shows the network control part of the radio network integrated system of the 2nd Embodiment of this invention. It is (a) whole block diagram which shows an example of the radio network integrated system of the 3rd Embodiment of this invention, (b) It is explanatory drawing of scheduling.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First embodiment of the present invention]
1 to 3 show a wireless network integration system and a wireless network integration method according to a first embodiment of this invention. The wireless network integration method of the first exemplary embodiment of the present invention is a method implemented by the wireless network integrated system of the first exemplary embodiment of the present invention.

[Overall Configuration of Wireless Network Integration System 10]
As shown in FIG. 1, a wireless network integration system 10 according to the first embodiment of the present invention includes a plurality of wireless communication network systems 11, an inter-base station communication network 12, a network controller (Hetero-Network Controller) 13, have.

  Each wireless communication network system 11 includes one or a plurality of base stations 21 and a plurality of terminals 22 provided so as to be able to perform wireless communication with each base station 21. Each base station 21 receives a positioning signal from the satellite 1 or a signal based on the positioning signal, and based on the received signal, a reference frequency and an absolute time (current time / second in accordance with world standard time) common to all base stations 21 are received. Unit timing pulse). Thereby, the base stations 21 of all the radio communication network systems 11 are synchronized with each other in the time / frequency domain.

  In the example shown in FIG. 1, each wireless communication network system 11 includes wide area cellular (Wular), WRAN, WLAN, and WPAN, but is not limited thereto. Each base station 21 includes not only a base station 21 such as a wide area cellular or WRAN, but also a WLAN access point (AP), each host of CSMA / CA, and the like. In a system in which a dedicated optical fiber is already laid, such as an existing cellular system, synchronization may be realized via the backbone. In addition, when it is difficult to install a satellite receiving antenna, such as a very small WPAN, it may be synchronized by supplying a timing pulse from a nearby WLAN AP or the like.

  As a satellite 1 to be used, a global navigation satellite system (GNSS) satellite 1 such as GPS in the United States, GLONASS in Russia, CNSS in China, QZSS (Quasi-Zenith Satellite System) in Japan can be used. In particular, as shown in the example of FIG. 1, QZSS is a system that enables reproduction of time and location information with extremely high accuracy over a wide area including urban areas. It is promising as a frequency synchronization means.

  As shown in FIG. 1, each wireless communication network system 11 has a communication area partially or entirely overlapped with a communication area of at least one other wireless communication network system 11. In addition, each terminal 22 can be used in each wireless communication network system 11 in a range where the communication areas of the wireless communication network system 11 overlap.

  The inter-base station communication network 12 is composed of a general-purpose IP network, and is connected to each base station 21 of each radio communication network system 11. The inter-base station communication network 12 connects all base stations 21 to each other.

  The network control unit 13 is connected to the inter-base station communication network 12 and is connected to all the base stations 21 via the inter-base station communication network 12. The network control unit 13 is configured to allocate radio resources to each radio communication network system 11 in the time domain and the frequency domain. Further, the network control unit 13 is configured to transmit the allocation information as information based on the reference frequency and the absolute time to each base station 21 of each wireless communication network system 11 via the inter-base station communication network 12. Has been.

  The network control unit 13 is composed of one, and one of them may cover the entire wireless communication network system 11, and it is composed of a plurality, each covering the wireless communication network system 11 in a predetermined range. May be. The allocation information includes, for example, a time expressed in absolute time (hours, minutes, seconds, etc.), a time zone (hours, minutes, minutes, etc.), and a relative value (absolute time) based on a 1-second pulse based on the world standard time. Transmission timing such as just +20 ms) per second, frequency channel, and the like.

  The wireless network integrated system 10 according to the first embodiment of the present invention is configured to perform wireless communication in each wireless communication network system 11 according to the assignment information transmitted by the network control unit 13. At that time, each wireless communication network system 11 is configured to perform wireless communication between each base station 21 and each terminal 22 by an access control method unique to each system. The system-specific access control method is, for example, a method in which each terminal 22 performs timing control and frequency control on the basis of the notification signal of the base station 21 and performs wireless communication at the obtained transmission timing.

[Configuration Example of Base Station 21]
An example of the configuration of each base station 21 is shown in FIG. As shown in FIG. 2, each base station 21 includes a satellite reception antenna 31a, a radio communication antenna 31b, a pair of radio communication function units 32a and 32b, a positioning / time measurement / timing generation unit 33, a communication control unit 34, and a host. A layer unit 35, a base station resource control unit 36, a terminal resource control unit 37, a scheduler unit (access control unit) 38, and a wired communication function unit 39 are provided.

  The satellite receiving antenna 31a is configured to receive a positioning signal from the satellite 1. The wireless communication antenna 31b is configured to be able to transmit / receive to / from each terminal 22 wirelessly. Each of the wireless communication function units 32a and 32b is connected to the satellite reception antenna 31a and the wireless communication antenna 31b, respectively, and converts the positioning signal from the satellite 1 and the reception signal from each terminal 22 into an analysis signal, It has a high frequency unit / modulation / demodulation unit for converting a signal to the terminal 22 into a signal for wireless transmission. The positioning / timing / timing generator 33 is configured to reproduce its own station position / reference frequency and current time using a positioning signal from the satellite 1. The communication control unit 34 is configured to adjust the transmission / reception timing and the channel (frequency) based on the reproduced time and frequency information S3 and an instruction from the scheduler unit 38.

  The upper layer unit 35 is configured to exchange the transmission / reception data S4 and S5 between the communication control unit 34 and the wired communication function unit 39, and buffer and framing the transmission / reception data S4 and S5 at that time. . The base station resource control unit 36 is configured to determine available resources based on the allocation information S6 from the network control unit 13. The terminal resource control unit 37 is configured to determine resources that can be used by each subordinate terminal 22 based on the allocation information S6 from the network control unit 13. The scheduler unit 38 is configured to perform scheduling and access control based on available resource information. The wired communication function unit 39 is configured to transmit and receive data to and from the network control unit 13 via the inter-base station communication network 12 that is a backbone network. In addition to these, each base station 21 has a communication function block unique to each wireless communication network system, but is omitted here.

[Operation of Wireless Network Integration System 10]
The operation of the wireless network integration system 10 of the first exemplary embodiment of the present invention will be described based on the configuration of the base station 21 in FIG. First, each base station 21 of each wireless communication network system 11 receives a positioning signal from the satellite 1 or a signal equivalent thereto, and based on the signal, a reference frequency common to all the base stations 21 (generally, The frequency (synchronized with the atomic clock mounted on the satellite 1) and the absolute time (world standard time, pulses in units of seconds, etc.) are acquired, and the time and frequency information S3 comprising them is reproduced. As a result, all base stations 21 share the common time and frequency information S3, and time / frequency synchronization is established.

  Next, the network control unit 13 allocates radio resources to each radio communication network system 11 in the time domain and the frequency domain. Further, the network control unit 13 transmits the allocation information S6 as information based on the reference frequency and the absolute time to each base station 21 of each wireless communication network system 11 via the inter-base station communication network 12. Allocation information S6 is generally specified by information on absolute time and frequency (channel), but may include information on space (eg, beam forming information), for example. The allocation information S6 is not linked to the timing pulse from the dedicated line, but consists of information according to the absolute time and the reference frequency.

  Based on the allocation information S6 transmitted by the network control unit 13, the resources (time / frequency) used for data transmission by the base station resource control unit 36 and the terminal resource control unit 37 and the resources used for transmission of each terminal 22 And decide. The determined resource information is sent to the scheduler unit 38, and scheduling is executed based on each access control method. The communication control unit 34 performs communication control using the transmission timing / frequency instruction from the scheduler unit 38 and the time and frequency information S3, and communicates with each terminal 22 via the wireless communication function unit 32b and the wireless communication antenna 31b. Perform wireless communication.

  An example of scheduling at this time is shown in FIG. FIG. 3 shows an example in which the two wireless communication network systems 11 of the system A and the system B are linked. Each system has a plurality of terminals 22 (terminals A1 to A5, B1 to B4) under its control. As shown in FIG. 3B, the network control unit 13 sends information on radio resources that can be used by the system A and the system B as the allocation information S6 (area surrounded by a dotted line in FIG. 3B). ) Is instructed. This information is generally less frequently updated, and is updated with a period of, for example, several seconds to several tens of seconds. Based on the allocation information S6, the base station resource control unit 36 and the terminal resource control unit 37 determine the uplink and downlink (not necessarily divided between uplink and downlink) of each system and notify the scheduler unit 38 .

  The scheduler unit 38 uses the scheduling method unique to each wireless communication network system or the access control method to instruct information on the available radio resources (area surrounded by a dotted line in FIG. 3B). To allocate to each terminal 22. In general, since the resource allocation process depends on the propagation path state of each terminal 22, a high-speed feedback process and a high-speed information update of about several milliseconds are required particularly in a mobile environment. Among the radio resources allocated by the network control unit 13, the same scheduling as when each radio communication network system 11 is isolated is performed for terminal control unique to each system and resource allocation for each terminal. .

  In the example of FIG. 3, it is the network control unit 13 and the base station resource control unit 36 that designate the radio resources that can be used by the system A and the system B (areas surrounded by dotted lines in FIG. 3B). It is the role of the scheduler unit 38 that performs the scheduling of each terminal 22 in the radio resource (area surrounded by the dotted line in FIG. 3B). . Even if the base station (AP) 21 and the terminal 22 are not necessarily distinguished as in CSMA / CA, the scheduler unit 38 uses CSMA / CA among the radio resources allocated to the system. Implemented access control.

[Operational effects of the first embodiment of the present invention]
In the wireless network integration system 10 and the wireless network integration method according to the first embodiment of this invention, each base station 21 acquires the reference frequency and absolute time common to all base stations 21 using the satellite 1. By doing so, all base stations 21 can synchronize time and frequency. Since each base station 21 independently reproduces the reference frequency and absolute time, all the base stations 21 can synchronize time and frequency by means other than the network without depending on the network. Thereby, as time and frequency allocation information, information based on the reference frequency and the absolute time need only be sent to the base station 21 of each wireless communication network system 11 via the inter-base station communication network 12. There is no need to send a timing pulse as a delay guarantee or a clock signal for frequency synchronization. For this reason, as an inter-base station communication network 12, not an expensive dedicated line for real-time communication for supplying timing pulses and clock signals but an inexpensive IP network for non-real-time communication can be used. Cost can be reduced.

  In the wireless network integration system 10 and the wireless network integration method according to the first embodiment of this invention, each wireless communication network system 11 and each base station 21 and each wireless communication network system 11 in the time domain and the frequency domain assigned by the network control unit 13. Since wireless communication is performed with the terminal 22, interference between the wireless communication network systems 11 can be prevented even if the communication areas of the wireless communication network systems 11 overlap. For example, unlike a cellular system designed on the assumption of planar development from the beginning, WRAN, WLAN, etc. that presuppose distributed control have very weak interference control functions between a plurality of base stations 21. On the other hand, with the rapid increase in wireless traffic, the number of WLAN APs arranged is rapidly increasing, and interference between base stations 21 causes a reduction in the efficiency of the entire network. In the future, it is considered that the AP placement density will be further increased, and therefore the inter-AP interference control according to the present invention is very effective.

  The radio network integration system 10 and the radio network integration method of the first exemplary embodiment of the present invention prevent timing synchronization uncertainty from occurring because all base stations 21 synchronize time and frequency. You can also. For this reason, communication between each base station 21 and each terminal 22 can be performed with high reliability. Moreover, frequency utilization efficiency can be improved and it can contribute to construction of a large capacity communication system.

  Further, the wireless network integration system 10 and the wireless network integration method of the first exemplary embodiment of the present invention include inter-system (inter-base station) resource allocation control for suppressing interference between the wireless communication network systems 11, Scheduling and access control for the terminals 22 under the base station 21 of each wireless communication network system 11 can be separated. That is, resource allocation control between the radio communication network systems 11 can be performed based on the allocation information of the network control unit 13, and scheduling / access control can be performed using an access control method unique to each radio communication network system. As a result, resource allocation between base stations, which is control in units of several seconds, and scheduling of terminals 22 that require control in units of milliseconds can be separated, and schedulers can be hierarchized, thereby reducing network construction costs. Thus, it is possible to achieve a moderate improvement in frequency utilization efficiency.

  In the wireless network integration system 10 and the wireless network integration method according to the first embodiment of this invention, a part of the inter-base station communication network 12 may be composed of a dedicated line or a wireless communication line. This includes, for example, a configuration in which a timing pulse is distributed from a base station 21 that can be synchronized by a positioning signal of the satellite 1 to a surrounding base station 21 that is invisible to the surrounding satellite by a dedicated line or a radio signal. Also in this case, the network construction cost can be reduced as compared with the case where all of the inter-base station communication network 12 is a dedicated line.

[Second embodiment of the present invention]
FIG. 4 shows a wireless network integration system and a wireless network integration method according to the second embodiment of this invention.
The wireless network integrated system according to the second embodiment of the present invention is similar to the wireless network integrated system 10 according to the first embodiment of the present invention. And a network control unit 13. In the following description, the same components as those in the wireless network integration system 10 according to the first embodiment of the present invention are denoted by the same reference numerals, and redundant description is omitted.

  Each terminal 22 of each wireless communication network system 11 is configured to measure communication quality information with a communicable base station 21 according to a predetermined measurement frequency or as necessary. In addition, each terminal 22 uses the measured communication quality information as probe information together with measurement position information at the time of measurement via the base station 21 of any one of the communicable base stations 21, to the network control unit 13. Configured to send to. Note that the communication quality information may be any information as long as it is information related to communication quality. For example, various indicators such as RSSI (received signal strength information) and SINR (signal to interference noise power ratio) are conceivable. .

  Each base station 21 of each wireless communication network system 11 is configured to transmit throughput related information necessary for calculating its own throughput to the network control unit 13. The throughput-related information includes, for example, the number of terminals 22 that can be connected to each base station 21, the number of connected terminals 22, the average traffic volume, and the like.

  Based on the probe information transmitted from each terminal 22 and the throughput related information transmitted from each base station 21, the network control unit 13 creates a communication quality database indicating the communication quality of each base station 21 at an arbitrary position. Configured to create. The communication quality database includes items such as SINR and reliability of each base station 21 at an arbitrary position, load state at a predetermined time, position of the base station 21, transmission output, cell radius, and various communication parameters. . The network control unit 13 obtains the priority order of the base stations 21 to which each terminal 22 can communicate based on the position of each terminal 22 from the created communication quality database, and for each terminal 22 and each base station 21, The map information including the communication quality information and priority information corresponding to each is edited.

  The network control unit 13 is configured to allocate radio resources to each radio communication network system 11 based on the edited map information. At this time, based on the communication quality database, the base stations 21 having a mutual interference relationship are obtained, and radio resources are allocated to the respective radio communication network systems 11 so as to suppress interference between the base stations 21 as much as possible. It is like that. The network control unit 13 is configured to transmit map information to the corresponding terminal 22 and base station 21.

[Configuration Example of Network Control Unit 13]
An example of the configuration of the network control unit 13 is shown in FIG. As shown in FIG. 4, the network control unit 13 includes a wired communication function unit 41, a communication quality information collection unit 42, a communication quality information statistical processing unit 43, a database creation / update unit 44, an inter-station interference analysis unit 45, and a map creation. A unit 46, an inter-base station resource allocation unit 47, and a map distribution unit 48.

  The wired communication function unit 41 is configured to transmit / receive data to / from each base station 21 via the inter-base station communication network 12 which is a backbone network. The communication quality information collection unit 42 is configured to receive the probe information transmitted from each terminal 22 and the throughput related information transmitted from each base station 21 via the wired communication function unit 41. Each time the communication quality information statistical processing unit 43 receives the probe information and the throughput related information, the communication quality information statistical processing unit 43 performs the statistical processing to obtain the communication quality distribution, the load information, and the like. The database creation / update unit 44 is configured to create a communication quality database indicating the communication quality of each base station 21 at an arbitrary position from the obtained communication quality distribution, load information, and the like. The database creation / update unit 44 is configured to update the communication quality database each time a new communication quality distribution, load information, and the like are obtained.

  The inter-station interference analysis unit 45 is configured to analyze the information of the latest communication quality database and determine the interference state between the base stations 21. The map creation unit 46 obtains the priority order of the base stations 21 to which each terminal 22 can communicate from the latest communication quality database, and information on communication quality and priority order information for each terminal 22 and each base station 21. Is created to create map information. Based on the interference information S45 from the inter-station interference analysis unit 45, the inter-base station resource allocating unit 47 obtains the base stations 21 having a mutual interference relationship, and suppresses the interference between the base stations 21 as much as possible. As described above, the radio resource is configured to be assigned to each radio communication network system 11 based on the priority information S46 of the map information created by the map creation unit 46. The map distribution unit 48 is configured to distribute map information to each corresponding base station 21 and each terminal 22.

[Operation of network control unit 13]
Based on the configuration of FIG. 4, the operation of the network control unit 13 of the wireless network integrated system according to the second embodiment of this invention will be described. First, probe information including communication quality information associated with a position, and throughput-related information such as the number of connected users are transmitted from each base station 21 and each terminal 22 via the inter-base station communication network 12 which is a backbone network. It is collected in the communication quality information collection unit 42. Such information is subjected to statistical processing such as suppression of fading effects and propagation environment fluctuations due to vehicle movement in the communication quality information statistical processing unit 43, and is held as a communication quality database in the database creation / update unit 44. The

  The inter-station interference analysis unit 45 analyzes the base stations 21 that have a relationship of causing interference with each other based on information in the communication quality database. On the other hand, the map creation unit 46 creates a map including the priority order of the connection destination base station 21 at the position of each terminal 22. This corresponds to a user assignment / guidance function between the base station 21 and the wireless communication network system 11. The map information also includes information regarding the number of connected users necessary for predicting throughput during connection. The map information is distributed by the map distribution unit 48 to each corresponding base station 21 and each terminal 22.

  The inter-base station resource allocation unit 47 performs resource control based on the inter-station interference information S45 and the priority order information S46. The inter-base station resource allocation unit 47 determines a communication resource to be allocated to each base station 21 so as to suppress interference between the base stations 21 determined to have an interference relationship. At this time, since the number of connected users / user allocation priority is closely related to the resource allocation between the base stations 21, the resource allocation is performed in consideration of the priority information S46. Further, the inter-base station resource allocation unit 47 notifies the base station 21 of the resource allocation information via the inter-base station communication network 12 which is a backbone network. Note that the resource allocation information is given as frequency (channel) information and absolute time information on the assumption that the base stations 21 are already synchronized.

[Operational effects of the second embodiment of the present invention]
The wireless network integration system and the wireless network integration method according to the second embodiment of the present invention are performed by analyzing the interference state between the base stations 21 and allocating resources by non-real time information transmission / reception without using a dedicated line. Interference control is possible, improving frequency utilization efficiency and reducing network construction costs. In addition, since radio resources are allocated based on probe information and throughput-related information, it is possible to allocate a radio communication environment with good communication quality and low load, and high reliability and high speed communication. . In addition, the line utilization rate can be increased.

  The wireless network integration system and wireless network integration method according to the second embodiment of the present invention can use the wireless communication system and wireless communication method disclosed in Japanese Patent Application No. 2013-250343 by the present inventors.

  Even if the wireless network integration system and the wireless network integration method according to the second embodiment of the present invention do not use the communication quality information measured by each terminal 22 according to a predetermined measurement frequency or as necessary, for example, the base station 21 in advance. At the time of installation, static communication quality information that determines a cell radius (signal reachable range) simply by examining a propagation state may be used.

[Third embodiment of the present invention]
FIG. 5 shows a wireless network integration system 50 and a wireless network integration method according to the third embodiment of this invention.
The wireless network integrated system 50 according to the third embodiment of the present invention is similar to the wireless network integrated system 10 according to the first embodiment of the present invention, and includes a plurality of wireless communication network systems 11 and inter-base station communication networks 12. And a network control unit 13. In the following description, the same components as those in the wireless network integration system 10 according to the first embodiment of the present invention are denoted by the same reference numerals, and redundant description is omitted.

  The network control unit 13 is configured to create one or a plurality of groups with a plurality of wireless communication network systems 11 having communication areas overlapping each other as one group. In addition, for each group, radio resources are allocated to each group and to the radio communication network system 11 that does not belong to any group so that the allocation time of each radio communication network system 11 to which the group belongs partially or entirely overlaps. Has been.

  For example, as shown in FIG. 5, when the wireless communication network system 11 includes two wide area communication systems (systems A and B) and three small communication systems (systems C, D, and E), the system A And system C, system A and system D, system B and system E are grouped, and radio resources are allocated to each group. Thereby, a radio | wireless resource is allocated in the same time slot | zone about each radio | wireless communication network system 11 in the same group.

  Each terminal 22 of the wireless communication network system 11 belonging to any group is configured to be usable by each wireless communication network system 11 belonging to the group in a range where the communication areas of the group overlap. Each of the terminals 22 divides information for wireless communication into a plurality of streams, and the divided information is based on the reliability and / or communication capacity of each wireless communication network system 11 belonging to the group. The wireless communication network system 11 is configured to perform wireless communication with the corresponding base station 21 in accordance with the allocation information distributed to each wireless communication network system 11 and transmitted by the network control unit 13. Each terminal 22 is not necessarily required to perform radio communication with the base stations 21 of a plurality of communication systems “simultaneously”. In addition, each terminal 22 may perform radio communication with the plurality of base stations 21 by time division operation.

  In the example shown in FIG. 5, a control channel is assigned to a wide area communication system (system A or B) in each group, a data channel is assigned to a small communication system (system C, D or E), and information transmitted / received by each terminal 22 is transmitted. The control signal and the data signal are divided, and each signal is transmitted and received through a separate channel (wireless communication network system 11).

  In wireless communication, high-efficiency signal transmission can be realized by combining a large-capacity data channel (U-Plane) with a highly reliable control channel (C-Plane) that can be small in capacity. Are known. In the wireless network integration system 50 and the wireless network integration method according to the third embodiment of the present invention, a plurality of wireless communication network systems 11 having different properties in terms of line capacity, reliability, coverage, and the like are used. By grouping on the basis of capacity, it is possible to assign wireless communication network systems 11 suitable for each pair, such as a data channel and a control channel, and perform efficient communication.

  The same concept of C / U-Plane separation is also recognized in 3GPP systems. However, in 3GPP, centralized control of small stations (such as RRE) is performed by a macro station, which realizes cooperative operation. Yes. On the other hand, in the wireless network integration system 50 and the wireless network integration method according to the third embodiment of the present invention, since each base station 21 independently realizes a synchronization function, a base such as an inexpensive IP network is provided. A cooperative operation between a wide-area system and a small-scale system can be realized only by notifying wireless resource information (available time / frequency) via the inter-station communication network 12.

DESCRIPTION OF SYMBOLS 1 Satellite 10, 50 Wireless network integrated system 11 Wireless communication network system 21 Base station 22 Terminal 12 Inter-base station communication network 13 Network control part

31a Satellite reception antenna 31b Wireless communication antenna 32a, 32b Wireless communication function unit 33 Positioning / time measurement / timing generation unit 34 Communication control unit 35 Upper layer unit 36 Base station resource control unit 37 Terminal resource control unit 38 Scheduler unit 39 Wired communication function Part

41 Wired Communication Function Unit 42 Communication Quality Information Collection Unit 43 Communication Quality Information Statistical Processing Unit 44 Database Creation / Update Unit 45 Inter-Station Interference Analysis Unit 46 Map Creation Unit 47 Inter-Base Station Resource Allocation Unit 48 Map Distribution Unit

Claims (10)

A wireless network integration system that integrates a plurality of wireless communication network systems each having one or a plurality of base stations and a plurality of terminals provided so as to be able to perform wireless communication with the base stations,
A communication network between base stations connected to the base station of each wireless communication network system;
A network control unit connected to the inter-base station communication network,
The base station is provided so as to be able to acquire a reference frequency and absolute time common to all base stations,
The network control unit allocates radio resources to each radio communication network system in a time domain and / or a frequency domain, and uses the allocation information as information based on the reference frequency and the absolute time, so that the inter-base station communication network Is configured to transmit to the base station of each wireless communication network system via
Each wireless communication network system is configured to perform wireless communication between each base station and each terminal according to the allocation information transmitted by the network control unit. . At least one wireless communication network system has a part or all of its communication area overlapping with the communication area of at least one other wireless communication network system;
2. The wireless network integrated system according to claim 1, wherein each terminal of the wireless communication network system with overlapping communication areas can be used in each wireless communication network system within a range in which the communication areas overlap.   The wireless network integration system according to claim 1 or 2, wherein the base station receives a positioning signal from a satellite and can acquire the reference frequency and the absolute time based on the positioning signal.   Each wireless communication network system is configured to perform wireless communication between the base station and each terminal by an access control method specific to each system according to the allocation information. The wireless network integrated system according to any one of the above. Each terminal measures communication quality information with a communicable base station, and uses the communication quality information as probe information together with measurement position information at the time of measurement. Configured to transmit to the network controller via a base station,
The base station of each wireless communication network system is configured to transmit throughput-related information necessary for calculating its own throughput to the network control unit,
The network control unit is configured to allocate the radio resource to each radio communication network system based on the probe information transmitted from each terminal and the throughput-related information transmitted from each base station. The wireless network integration system according to any one of claims 1 to 4, wherein: The base station of each wireless communication network system is configured to transmit throughput-related information necessary for calculating its own throughput to the network control unit,
The network control unit assigns the radio resource to each radio based on probe information including communication quality information of each base station at an arbitrary position obtained in advance and the throughput-related information transmitted from each base station. The wireless network integrated system according to any one of claims 1 to 4, wherein the wireless network integrated system is configured to be assigned to a communication network system.   The network control unit creates a communication quality database indicating communication quality of each base station at an arbitrary position based on the probe information and the throughput related information, and based on the position of each terminal from the communication quality database In addition to determining the priority order of the base stations with which each terminal can communicate, for each terminal and each base station, edit the map information including the communication quality information and the priority order information corresponding to each, 7. The radio according to claim 5, wherein the radio resource is allocated to each radio communication network system based on map information, and the map information is transmitted to a corresponding terminal and base station. Network integration system.   The network control unit obtains base stations in a relationship of causing interference with each other from the communication quality database, and allocates the radio resources to each radio communication network system so as to suppress interference between the base stations as much as possible. The wireless network integration system according to claim 7. The network control unit creates one or a plurality of groups with a plurality of wireless communication network systems having communication areas overlapping each other as one group, and the assigned time of each wireless communication network system to which each group belongs is set to one. The wireless resource is configured to be assigned to each group and a wireless communication network system that does not belong to any group so as to overlap with each other,
Each terminal of a wireless communication network system belonging to any group can be used in each wireless communication network system belonging to the group as long as the communication areas of the group overlap, and a plurality of pieces of information for wireless communication can be obtained. Each of the divided information is distributed to each wireless communication network system based on the reliability and / or communication capacity of each wireless communication network system belonging to the group, and transmitted by the network control unit The wireless network integration system according to any one of claims 1 to 8, wherein the wireless network integration system is configured to perform wireless communication with a corresponding base station in accordance with the allocation information. A wireless network integration method for integrating a plurality of wireless communication network systems each having one or a plurality of base stations and a plurality of terminals provided so as to be able to perform wireless communication with the base stations,
A communication network between base stations connected to the base station of each wireless communication network system;
A network control unit connected to the inter-base station communication network,
The base station acquires a reference frequency and an absolute time common to all base stations,
The network control unit allocates radio resources to each radio communication network system in a time domain and / or a frequency domain, and uses the allocation information as information based on the reference frequency and the absolute time, so that the inter-base station communication network To the base station of each wireless communication network system via
Each wireless communication network system performs wireless communication between each base station and each terminal according to the allocation information transmitted by the network control unit.