JP2016123126A - Different system coexistence method and radio gateway device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve coexistence between a WRAN (IEEE802.22) and a WLAN (IEEE802.11af).SOLUTION: A network management unit equipped in a WRAN base station communicates with a differentiate system coexistence function unit equipped in a relay station, using a WRAN radio channel, so that a frequency channel used in a WLAN is determined and managed. Typically, in regard to the frequency channel, a WRAN and the WLAN synchronize a transmission stop period (QP), and absence confirmation of a primary user is performed in the QP. When the WRAN shares an identical frequency with the WLAN in time division, the base station 1 does not transmit a signal for frame control, to put a WRAN terminal into a non-transmission state, and during the above period, the WLAN performs communication. The relay station 2 notifies in advance the WLAN terminal of a WRAN communication period as the QP.SELECTED DRAWING: Figure 6

Description

The present invention provides a plurality of different white space use radios in a white space use radio communication system that uses radio waves flexibly while sufficiently avoiding the influence on existing business (primary system, primary user, primary use system). The present invention relates to a heterogeneous system coexistence method and a wireless gateway device that enable use of the same frequency in a system.

As a new frequency utilization method that solves the problem of frequency depletion, in recent years, even for frequencies that have already been allocated, the frequency band (white space) that can be used spatially and temporally,
Research and development of wireless systems using white space, such as cognitive radios, that flexibly use radio waves while sufficiently avoiding the impact on existing business.

For example, as a wireless system using white space, IEEE802.22 (Non-Patent Document 1)
Standardization) and IEEE802.11af are being standardized. In order to avoid impact on existing business (such as TV broadcasting) in these standards,
1) Database (Incumb) where each wireless station manages white space on the IP network
ent DB, whitespace database, WSDB) and network manager to obtain available frequency list and maximum transmittable power based on own location information,
2) It is defined that communication is performed after confirming that there is no existing station using the frequency to be used by the spectrum sensing function (signal detection function).
In order to perform these efficiently, it is considered that the bandwidth and channel arrangement are the same as those of television broadcasting.

By the way, each standard has a different target service. IEEE802.22 aims to construct a WRAN (Wireless Regional Area Network) that covers a wide area by long-distance wireless transmission. WMAN (Wireless Metropolitan Area Network) covering a medium-sized area by wireless transmission over a distance and WLAN (
The goal is to build a Wireless Local Area Network. These systems are, for example, IEEE, which is a long-distance transmission facility as a backhaul line for Internet connection.
802.22 IEEE8 as a short-range wireless transmission facility for covering each home and town using WRAN
02.11af A method using WLAN is considered. Therefore, control for coexistence without interference between IEEE802.22 and IEEE802.11af wireless systems is required (see, for example, Patent Documents 1 to 3 and Non-Patent Document 2).

JP 2012-29177 A JP 2011-193422 A JP 2011-176508 A IEEE Std 802.22-2011 Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications: Policies and Procedures for Operation in the TV Bands, (USA) ), IEEE Standardization Association, July 27, 2011 Tuncer Baykas, “IEEE 802.19.1 Overview”, [online], IEEE 802.19 Working Group, [searched February 18, 2012], Internet <URL: http://ieee802.org/19/pub/Workshop/2_Baykas -NICT.pdf>

For example, if the only frequency available as white space is IEEE 80
2.22 Consider an IEEE802.11af WLAN system in the WRAN service area. In such a case, the following problems can be considered.

(1) Since IEEE802.22 and IEEE802.11af radio stations do not have the reception function of each other's system, it is possible to detect the presence of other systems by frequency sensing. It cannot be distinguished whether it is another system (secondary user) that uses the space. In such a case, although both are frequencies that can be used, it is determined that the frequency is not usable and communication is impossible.

(2) Even if the mutual systems can be recognized by a signal processing technique such as feature detection, there is no protocol for the two systems to coexist, so frequency sharing cannot be performed. This is because IEEE802.22, which uses OFDMA / TDD as the access method, periodically transmits radio waves, so the access method CSMA / CA (Carrier
(Sense Multiple Access with Collision Avoidance)
IEEE802.11af, which can communicate only during a short time when IEEE802.22 does not communicate, causes unfairness in the use of bandwidth. Also, when IEEE802.22 does not communicate, IEEE802.11
The period for sensing a primary user (Quiet Period)
: QP) and uplink / downlink switching periods. If IEEE802.11af starts transmission during this period, IEEE802.22 may have problems such as false detection or oversight of the primary user, or interference during the data transmission / reception period (up / down frame).

As another example, when providing broadband lines to households such as suburbs and remote areas, a wired network such as FTTH (Fiber To The Home) is not used, but a method of providing it via a wireless network. Conceivable. In such a case, a long-distance transmission facility as a backhaul line and a medium / short-distance transmission facility used by each home or the like cooperate, and a method based on interconnection with different wireless systems or multi-hop transmission is considered as a solution. For this reason,
Even under such circumstances, it is necessary to coexist two systems that should be in a cooperative relationship.

The present invention has been made in view of the above problems. In the situation where IEEE802.22 and IEEE802.11af are mixed as described above, different wireless wireless systems using white space can coexist. .22 The purpose is to provide technology for realizing multi-hop transmission between systems and coexistence between systems, such as using WRAN as a backhaul line.

According to one aspect of the present invention, a network management unit provided in a base station and a different system coexistence function unit provided in a relay station communicate using an IEEE802.22 wireless line, and IEEE802.
By coordinating and managing the frequency channels used by 11af WLAN, the frequency is shared and coexistence is realized.

Also, in a preferred aspect of the present invention, IEEE802.22 WRAN is also used for the frequency channel.
And the IEEE802.11af WLAN synchronize the transmission stop period (Quiet Period: QP) and confirm the absence of the primary user in the QP, thereby preventing the secondary user from being erroneously detected as the primary user.

In addition, when IEEE802.22 WRAN and IEEE802.11af share the same frequency in time division, I
The base station of EEE802.22 sets the IEEE802.22 terminal (CPE: Customer Premise Equipment) to the non-transmission state by making the signal for frame control non-transmission, and during this time, the IEEE802.11af WLAN
Communicate. During the period in which IEEE802.22 communicates, the IEEE802.11af WLAN notifies the IEEE802.11af terminal in advance as a QP so that it does not transmit. During this period, the IEEE802.22 WRAN
Communicate.
By the above means, coexistence of IEEE802.22 and IEEE802.11af is realized.

According to the present invention, interconnection and coexistence between wireless systems using white space of different standards are possible.

The block diagram of the white space utilization system which concerns on one Embodiment of this invention. The block diagram of the base station 1 which concerns on one Embodiment of this invention. The block diagram of the relay station 2 which concerns on one Embodiment of this invention. The flowchart of a coexistence operation | movement when there exists a channel which can use only IEEE802.11af. The flowchart in case IEEE802.22 and IEEE802.11af can use different channels. The flowchart of the coexistence operation | movement when IEEE802.22 and IEEE802.11af cannot use a different channel.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram of a white space utilization system according to the present embodiment.
The white space utilization system of the present embodiment includes a base station (BS) 1 that manages and controls IEEE802.22 WRAN cells, a relay station (RS) 2, a terminal (MS, STA) 3, an Internet 4 and white space database (WSDB) 5. In the white space utilization system of this example, the relay station 2 communicates with the base station 1 by IEEE802.22 and communicates with the terminal 3 by IE.
While communicating with EE802.11af, the communication performed between the base station 1 and the terminal 3 is relayed. The relay station 2 that connects different systems in this way is also called a gateway.

FIG. 2 is a block diagram of the base station 1. Base station 1 includes antenna 101 and IEEE802.22.
IEEE802.22 transmission / reception unit 102 having a transmission / reception function of a compliant base station, IEEE802.22 frequency management unit 103 which is a spectrum manager (SM) compliant with IEEE802.22, and a relay connected to the base station 1 Network management unit 10 for controlling the frequency channel used for transmission of the network (IEEE802.11af WLAN) managed by the station, transmission possible timing, and maximum transmission power
4, a connection terminal 105 connected to the Internet, and an interface unit 106 serving as an interface between the function units (102 to 104) and the connection terminal 105.
The IEEE802.22 frequency management unit 103 is a core functional unit in the cognitive radio base station, maintains information on frequencies that can be used as IEEE802.22, and the IEEE802.22 itself and neighboring IEEE802.22.
Manage the list of base station operation channels and backup channels, manage the QP schedule,
Implement coexistence function between IEEE802.22.
The network management unit 104 is an IEEE802.22 maintained by the IEEE802.22 frequency management unit 103.
In addition to managing available frequency channels of IEEE802.11af WLAN by referring to and considering available frequency information, the channel assigned to IEEE802.11af is used as interference information, as necessary, or as a self or virtual IEEE802.22 base. The IEEE802.22 frequency management unit 103 is notified that the channel is in operation, preparation, or candidate channel.

FIG. 3 is a block diagram of the relay station 2. The relay station 2 includes an antenna 201 and IEEE802.22.
IEEE802.22 CPE function unit 202 having a terminal function compliant with IEEE802.11af AP function unit 203 having a WLAN access point function (including a routing function) compliant with IEEE802.11af, and the network management unit 104. A different system coexistence function unit 204 having a function of requesting and acquiring (frequency channel) and an interface unit 205 serving as an interface of each function unit (202 to 204). As a result, the relay station 2 uses IEEE 802.11a.
f Communication within WLAN is possible, and IEEE802.22 WRAN can be used as a backhaul.
The routing function is necessary when connecting different networks.
A functional unit (interface unit 205 or 106) other than the 11af AP functional unit 203 may be provided. The different system coexistence function unit 204 is SNMP (Simple Network Management Protocol).
And other well-known techniques (neighbor discovery protocol etc.), information (address etc.) necessary for connection to the network management unit 104 is obtained by itself.

In FIG. 3, the antenna 201 includes an IEEE802.22 CPE function unit 202 and an IEEE802.11af AP.
Different antennas are connected to the function unit 203. However, when the directivity, gain, and the like may be the same, one antenna may be shared using a distributor, a combiner, or the like.

In the present embodiment, the network management unit 104 provided in the base station 1 and the different system coexistence function unit 204 provided in the relay station 2 communicate with each other using the IEEE802.22 wireless line, whereby IEEE802. .11af
It is characterized by determining and managing frequency channels used by the WLAN. Another feature is that the IEEE802.22 WRAN and the IEEE802.11af WLAN synchronize the transmission stop period (Quiet Period: QP) for the frequency channel in order to correctly detect the primary user.

Hereinafter, the coexistence flow of IEEE802.22 WRAN and IEEE802.11af WLAN will be described for each of three cases with reference to FIGS. 4, 5, and 6. In each of the three cases, when there is a channel that can use only IEEE802.11af (Case 1), there are multiple channels that can be used and IEEE802.22 WRAN.
And IEEE802.11af WLAN can use different channels (Case 2), and only one channel can be used and IEEE802.22 WRAN and IEEE802.11af WLAN cannot use different channels (Case 3). IEEE802.22 WRAN and IEEE802.1 in cases 1 and 2
The frequencies that can be used by each system of 1af WLAN are assumed as shown in the table below.

Under this assumption, IEEE802.22 WRAN can use f1 and f2, and f3 and f4 cannot be used to protect interference to the primary user. IEEE802.11af WLAN uses frequency channels f1, f2
, F4 can be used as white space, and the frequency channel f3 cannot be used for interference protection to the primary user.
Here, the reason why IEEE802.11af WLAN can be used for frequency channel f4 and IEEE802.22 WRAN cannot be used is due to the difference in transmission power, and IEEE802.11af WLAN is intended for mid-to-short distance communication. This is because communication is possible with lower power than IEEE802.22 WRAN, and communication is possible without causing interference to the primary user. The reverse case (when there is a channel that can use only IEEE802.22) is not assumed. If there is a channel that can be used only by IEEE802.22, IEEE802.22 WRAN can use the channel arbitrarily according to the standard.

The WSDB 5 maintains information as shown in Table 1 or information from which this table can be derived.
For example, the availability of the frequency channel (presence / absence of the primary system) and the maximum allowable transmission power when possible are held for each frequency channel, and the maximum allowable transmission power is the minimum required power for each system. It may be something to compare.
Note that there may be a case where the channel arrangement in IEEE802.11af is different from that in IEEE802.22 (or the primary system) (for example, the channel interval is 4 MHz for the former and 6 MHz for the latter). In that case, when IEEE802.22 WRAN and IEEE802.11af WLAN use different channels, it means that the occupied bands of those channels do not overlap, and IEEE802.22 WRAN and IEEE802.11af WLAN are the same channel. Is used, it means that the occupied bands of those channels are overlapped.

[Case 1: When there is a channel that can use only IEEE802.11af]
FIG. 4 illustrates details of the coexistence operation when there is a channel that can be used only by IEEE802.11af.

[S401]
First of all, the relay station 2 establishes a backhaul line with the base station 1 to establish IEEE802.22.
The network entry is made to IEEE802.22 WRAN using the CPE function 202.
In this example, IEEE802.22 WRAN communicates using the frequency channel f1, and the relay station 2 transmits the SCH (Superframe Control Header) or CBP (Coe) that the base station 1 transmits using the frequency f1.
by receiving messages such as xistence Beacon Protocol)
Recognizes the channel used by RAN (operating channel) and backup channel (backup channel). The information is IEEE802.22CPE function part 20
2 and the different system coexistence function unit 204.
In addition to the network entry to IEEE802.22 WRAN, the relay station 2 notifies the network management unit 104 of the base station 1 that it is an IEEE802.11af WLAN relay device.

[S402]
After establishing communication between the base station 1 and the relay station 2, the IEEE802.11af AP function unit 203 of the relay station 2 uses the different system coexistence function to obtain a list of frequency channel candidates that can be used by the IEEE802.11af WLAN. The unit 204 is instructed to access the WSDB 5 and acquire a channel that can be used as a white space.
Upon receiving the command, the different system coexistence function unit 204 accesses the WSDB 5 and reads IEEE802.11af.
A list of frequency channel candidates that can be used by the WLAN is acquired, and the acquired information is stored.
In this way, the IEEE802.11af function unit 203 does not directly access the DB using the IEEE802.22 WRAN wireless line, but uses the different system coexistence function unit 204 like a gateway or a proxy server. Try to get white space information.

The different system coexistence function unit 204 may use the network management unit 104 as a gateway or a proxy server, and the network management unit 104 may obtain a list of frequency candidates as a proxy and notify the different system coexistence function unit 204. Therefore, the network management unit 104 may be installed as a server or the like in the Internet 4 without being provided in the base station 1. The network management unit 104 can reduce the load on the WSDB 5 by caching the white space information inquired of the IEEE802.22 frequency management unit 103 or the WSDB 5.

[S403]
When the different system coexistence function unit 204 of the relay station 2 acquires the channel list that can be used by the IEEE802.11af WLAN, it notifies the network management unit 104 of the base station 1 of the acquired list,
The base station 1 returns a reception confirmation message.
In step S402, if the different system coexistence function unit 204 obtains the list by proxying to the network management unit 104 by a gateway, proxy server function, etc., the network management unit 104 stores the list at that time. Well, this step S
403 is unnecessary.

[S404]
The different system coexistence management unit 204 of the relay station 2 compares the channel list that can use the IEEE802.22 WRAN and the channel list that can use the IEEE802.11af WLAN. IEEE802.11af WL
If there is a channel that can be used only by AN and the channel satisfies the system-defined communication quality, it is determined that the channel is used, and the channel is designated as IEEE802.11af AP function unit 203.
Notify
In this example, a frequency channel f4 that is a channel that can be used in the IEEE802.11af WLAN is used. IEEE that received a notification from the different system coexistence management unit 204 that the frequency channel f4 is available
The 802.11af AP function unit 203 periodically checks the absence of the primary user so that no transmission period (Q
uiet Period: QP) period and period are set and stored, and the different system coexistence management unit 204 is notified. The QP period is preferably set to an integer multiple of the period of the IEEE802.22 WRAN radio frame (10 ms) or the period of the superframe (160 ms).
When there is no channel that can be used only by the IEEE802.11af WLAN, the frequency used for communication is determined by the procedure shown in FIGS. (Details will be described later.)

[S405]
The different system coexistence management unit 204 of the relay station 2 notifies the network management unit 104 of the base station 1 of the use decision of the frequency channel f4 and information on the QP. The base station 1 that has received the notification
A reception confirmation message is returned to the relay station 2, and the network management unit 104 notifies the IEEE802.22 frequency management unit 103 of the received information on the QP.
This step makes it possible to synchronize the QP for the frequency channel f4.
That is, the IEEE802.22 frequency management unit 103 performs out-band sensing of f4 in the QP period of f1 that matches the QP period of the IEEE802.11af WLAN. The QP period that could not be matched may be used for sensing other than f4. This allows IEEE802.22 WRA
N can prevent the IEEE802.11af WLAN from being falsely detected as a primary user.
E802.22 WRAN can correctly confirm the absence of the primary user. In addition, when the WSDB5 channel list is updated and the IEEE802.22 WRAN can use the frequency channel f4, sufficient sensing is performed at a timing that is strongly assumed to be used by the IEEE802.11af WLAN based on the QP timing. . As a result, the detection of the presence of the IEEE802.11af WLAN fails and the IEEE802.11a
f It is also possible to more reliably prevent interference with the WLAN.
Note that it is not necessary to perform QP synchronization for frequencies other than the frequency channel f4, and for the frequency f1, the absence of a primary user may be confirmed by a QP already set by IEEE802.22 WRAN.

[S406]
The relay station 2 authenticates and establishes a connection with the terminal 3 according to the procedure defined by IEEE802.11af.

[S407]
The terminal 3 stores the QP information acquired at the time of establishing a connection with the relay station 2 according to the procedure of IEEE802.11af.

[S408]
The relay station 2 performs IEEE802.11af WLAN communication using the frequency f4. In parallel with this, IEEE8
02.22 WRAN can communicate using frequency f1, and the two systems can coexist. The IEEE802.11af WLAN terminal 3 can be connected to the Internet 5 via the base station 1 and the relay station 2.

[S409]
The relay station 2 confirms the absence of the primary user during the period (QP) determined in step S405. When a primary user is detected, use of that channel as a protection channel is prohibited.
When confirming whether IEEE802.22 WRAN can be used as a white space for the frequency channel f4, the absence of the primary user is confirmed by synchronizing the QP of the frequency channel f4.
Thereafter, when a further bandwidth request occurs, the steps S404 and S405
Get the channel. Even if there is no new bandwidth request, S405 is notified periodically or whenever the next QP schedule is determined, and the IEEE802.22 frequency management unit 103 deletes the QP after a predetermined time from the notification as invalid. It may be.

[Case 2: When IEEE802.22 WRAN and IEEE802.11af WLAN can use different channels]
FIG. 5 illustrates the details of the coexistence operation when IEEE802.22 WRAN and IEEE802.11af WLAN can use different channels, that is, when there are two or more channels that can be used as white space.

[S501 to S504]
This is the same as steps S401 to S404.

[S505]
In step S504, if there is no channel that can be used only by the IEEE802.11af WLAN, the different system coexistence function unit 204 of the relay station 2 performs the network management unit 10 of the base station 1.
4. Band request (channel allocation request) is made.
Channels not used by IEEE802.22 WRAN can be used without interference by IEEE802.11af WLAN, so you can select any channel from these channels, specify the channel, and request allocation. The channel management may be left to the network management unit 104 without specifying the channel.

[S506]
The network management unit 104 of the base station 1 that has received the bandwidth request considers whether or not to give interference to other IEEE802.22 WRAN existing in the vicinity when the allocation channel is designated. It is determined whether or not the channel can be used. If the assigned channel is not designated, an arbitrary assigned channel is selected (in this embodiment, f2 is selected).
In addition, the network management unit 104 considers the neighboring IEEE802.22 WRAN channel usage status, etc., and can perform transmission in the assigned channel (active frame) and QP so as not to interfere with other systems. Determine the maximum power allowed (if necessary). At this time, when the IEEE802.22 WRAN uses a plurality of channels, the channel being used may be released and selected to be assigned to the IEEE802.11af WLAN.
The determined QP is notified / set to the IEEE802.22 frequency management unit (SM) 103. As a result, it is possible to prevent the IEEE802.22 system from performing transmission using f2 when IEEE802.11af is QP.
Further, the BS001 may include information that f2 is an active channel in a CBP that is periodically transmitted, thereby preventing another IEEE802.22 WRAN from using the frequency channel f2.

[S507]
The base station 1 notifies the relay station 2 of the determined assigned channel, transmission possible timing, and QP.
If a channel is specified when requesting bandwidth and it is determined that the channel cannot be used,
Information is notified to the relay station 2 that there is no assigned channel (unusable).
The relay station 2 that has received the allocation result returns a reception confirmation message to the base station 1.

[S508]
The IEEE802.22 CPE function unit 202 of the relay station 2 that has received the allocation result notifies the different system coexistence function unit 204 and the IEEE802.11af function unit 203 of the allocated channel, transmission possible timing, and QP, and stores / sets it there. Done. This transmission timing and QP are based on neighboring IEEE802.22 W
Since it is determined in consideration of the RAN channel usage situation, it is possible to prevent interference with neighboring IEEE802.22 and further prevent false detection and false alarm of the primary user in QP.

[S509]
The IEEE802.11af function unit 203 of the relay station 2 authenticates and establishes a connection with the terminal 3 according to a procedure defined by IEEE802.11af.

[S510]
The terminal 3 stores the QP information acquired at the time of establishing a connection with the terminal 3 according to the procedure of IEEE802.11af.

[S511-S512]
In the determined transmittable period and QP, IEEE802.22 and IEEE802.11af confirm the absence of communication and the temporary system, respectively. In the present embodiment, the transmission period of IEEE802.22 and IEEE802.11af and the QP are synchronized, but synchronization is not essential because the frequency used is different.

[Case 3: When IEEE802.22 WRAN and IEEE802.11af WLAN cannot use different channels]
In FIG. 6, when IEEE802.22 WRAN and IEEE802.11af WLAN cannot use different channels,
For example, details of the coexistence operation when it is assumed that there is only one channel that can be used as white space and only the frequency channel f1 can be used will be described. In this embodiment, when there is only one channel that can be used, the channel is shared in a time-sharing manner, and each system uses the channel in frame units defined by IEEE802.22.

[S601 to S605]
This is the same as steps S501 to S505.

[S606]
The network management unit 104 of the base station 1 that has received the bandwidth request uses the frequency channel f1 to perform time division sharing with the IEEE802.11af WLAN. Therefore, the transmission timing (frame), QP cycle, and period of the IEEE802.11af WLAN are set. decide. The determined information is notified to the frequency management unit 103. In addition, information is added to normal SCH and CBP as a frame used by IEEE802.22 WRAN as an active frame, but in the present invention, a frame used by IEEE802.11af is also active without being distinguished from IEEE802.22 WRAN. Information is added as a frame. Thereby, it is possible to prevent the use of a frame assigned to IEEE802.11af by the neighboring IEEE802.22 WRAN.

[S607 to S610]
This is the same as steps S507 to S510. However, a plurality of relay stations 2 can share the same channel, and in this case, the allocated channel, transmission possible timing, and QP that are notified to each relay station in S607 are common.
In addition, since the terminal 3 generally does not perform the absence confirmation (sensing) of the primary user, the primary user is not notified to the terminal 3 even if all frames other than those that can be transmitted by IEEE802.11af are notified and set. Since there is no false detection, the period is set to QP (which may be a period in which transmission is prohibited).

[S611]
The IEEE802.11af WLAN IEEE802.11af AP function unit 203 and the terminal 3) perform communication using the frequency channel f1 in the allocated transmission possible period.
IEEE802.22 WRAN waits without transmission. Since the base station 1 notifies this frame as an active frame of the base station 1 using SCH or CBP, the IEEE802.22 CPE is IEEE802.22.
Although it is recognized that a WRAN frame is being transmitted, frame control information such as a frame preamble, FCH (Frame Control Header), DSMAP, and USMAP is not actually transmitted from the base station 1. Therefore, CPE is not transmitted in this frame, and IEEE802.11af
There is no interference to the WLAN.

[S612]
IEEE802.22 WRAN performs communication using the frequency channel f1 in the allocated transmission available period.
The IEEE802.11af WLAN (IEEE802.11af AP function unit 203 and terminal 3) stands by without transmission.
Non-transmission can be realized by various known methods. For example, PCF (Point Coordina) is used as an access method.
option Function), a CFP (Contention Free period) is set in accordance with the period in which IEEE802.22 WRAN is active, and notified with a parameter included in a beacon or Probe Response, and during CFP, Do not give access rights to all terminals 3 (C
This can be realized by not transmitting F-Poll.

[S613]
IEEE802.22 WRAN and IEEE802.11af WLAN are not transmitted, and the absence of the primary user is confirmed.
If the IEEE802.11af WLAN does not require spectrum sensing (because the used frequency is confirmed by the WSDB5), the QP of the IEEE802.11af WLAN at this step may be simply no transmission. IEEE 802.22 WRAN QP has two types: a short-period QP for “Intra-frame sensing” and a long-period QP for “Inter-frame sensing”. In the case of a short period QP, the IEEE802.11af WLAN makes a communication advance notice according to the RTS / CTS procedure, and can actually realize no transmission during the period by not performing communication.

As described above, by using the relay station as in this embodiment, IEEE802.22 and IEEE802.
11af can coexist.

DESCRIPTION OF SYMBOLS 1 ... Base station (BS), 2 ... Relay station (RS), 3 ... Terminal (MS, STA), 4 ... Connection terminal (port), 5 ... White space database (WSDB),
DESCRIPTION OF SYMBOLS 101 ... Antenna, 102 ... IEEE802.22 transmission / reception part, 103 ... IEEE802.22 frequency management part, 104 ... Network management part, 105 ... Connection terminal (port) terminal, 106 ... Interface part 106,
DESCRIPTION OF SYMBOLS 201 ... Antenna, 202 ... IEEE802.22 CPE function part, 203 ... IEEE802.11af AP function part, 204 ... Different system coexistence function part, 205 ... Interface part.

Claims (1)

Each of the first and second wireless systems having different schemes is a wireless gateway device that relays communication performed using a white space frequency,
  A first system terminal unit that wirelessly communicates with a base station of the first wireless system as a terminal of the first wireless system;
  A second system AP unit that wirelessly communicates with a terminal of the second wireless system as a base station of the second wireless system;
  When logging in to the base station of the first radio system, requesting a frequency channel, causing the second system AP unit to use the acquired frequency channel, and when transmission timing is determined in the acquired frequency channel Includes a different system coexistence function unit that sets the second system AP unit to set the second wireless system to a non-transmission period over all periods other than the timing,
  The different system coexistence function unit cannot be used when it finds a frequency channel that cannot be used in the first radio system in the list of frequency channels that can be used by the second radio system acquired from a database provided outside. The frequency channel used by the second system AP unit is used by the second system AP unit, and the frequency channel and the non-transmission period used by the second system AP unit are notified to the base station of the first radio system,
  When no frequency channel that cannot be used in the first wireless system is found in the list, the different system coexistence function unit causes the second system AP unit to use the acquired frequency channel and sets a transmission stop period. A wireless gateway apparatus that is synchronized with the first wireless system transmission stop period.

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