WO2012120645A1

WO2012120645A1 - Pon system, optical line terminal device and optical transmission path terminal device

Info

Publication number: WO2012120645A1
Application number: PCT/JP2011/055392
Authority: WO
Inventors: 大輔真下; 淳栖川; 池田　博樹
Original assignee: 株式会社日立製作所
Priority date: 2011-03-08
Filing date: 2011-03-08
Publication date: 2012-09-13

Abstract

In a PON system which accommodates a wireless base station in a PON, when a wireless terminal moves into the area of another base station during communication, it is impossible to perform a hand over without cutting off the communication because an ONU discards any downlink data except for corresponding LLID. The present invention provides a hand over method, wherein the LLID is given to each user terminal and the OLT and the ONU maintain information about the MAC address and the LLID of the user terminal, and thus communication is not cut off when a wireless terminal has moved, by performing the communication in a PON section on the basis of the same LLID as the LLID before the movement.

Description

PON system, optical line terminator and optical transmission line terminator

The present invention relates to a wireless terminal handover technique when a wireless base station is accommodated in a PON system.

The PON (: Passive Optical Network) system is a high-speed / high-capacity network that shares optical fiber and OLT (Optical Network Terminal, subscriber accommodation equipment) with multiple ONUs (Optical Network Unit, optical subscriber termination equipment). It is an optical access system and supports the current FTTH service as a technology that can control the cost per user. Downlink transmission from the OLT to the ONU employs a time division multiplexing (TDM) method using continuous signals. The OLT assigns an LLID (: Logical Link ID) to each ONU, and the ONU reads the LLID inserted in the data to determine the data addressed to itself. On the other hand, uplink transmission from ONU to OLT employs a time division multiple access (TDMA) method in order to prevent signal collision. Since the distance between the ONU and the OLT differs depending on the user, the OLT receives different levels of burst signals. Due to the expansion of FTTH service needs and the advancement of transmission technology, the next-generation PON system is speeding up. In the PR-30 standard of 10G-EPON, which has been standardized in IEEE802.3av task force in 2009, Non-Patent Document 1 defines a transmission speed of 10 Gbps, a maximum number of branches of 32, and a maximum transmission distance of 20 km.

In addition, broadband wireless access (BWA) technology is rapidly expanding due to its high flexibility, enabling broadband services to be provided to users with conventional wired connections and users in sparsely populated areas. Yes. With BWA, technologies such as HSPA (High Speed Packet Access) and WiMAX (Worldwide Interoperability for Microwave Access) have appeared, and the communication speed has improved rapidly. Therefore, it is expected that BWA services will continue to expand globally.

As the communication speed of the radio access network improves, it will be necessary to increase the bandwidth of the mobile backhaul that accommodates it. Therefore, a wireless base station accommodating PON system that accommodates wireless base stations such as LAN (Local Area Network) and WiMAX using a PON system for mobile backhaul is currently disclosed (for example, Patent Document 1 and Patent Document 2). ). By taking advantage of the high speed and flexibility of PON, it is possible to efficiently achieve higher bandwidth for mobile backhaul.

One of the important technologies in wireless access is handover. Since the wireless user may move, if the wireless user moves outside the area of the communicating base station, it is necessary to switch communication with the base station in the new area. There are two types of handover: hard handover in which communication disconnection occurs during switching and soft handover in which communication disconnection does not occur. In recent years, realization of soft handover has become more important due to the spread of applications requiring real-time characteristics such as VoIP (Voice over IP) and video.

JP 2009-272787 A JP 2008-72714 A

The PON system generally inserts LLID for each destination ONU into a MAC frame and establishes a logical P2P link between OLT-ONUs for communication. The ONU requests bandwidth allocation based on the amount of data transmitted from the lower network for the uplink data, inserts the LLID, and transmits it to the OLT. On the other hand, for downlink data, the ONU transmits only the data in which the LLID addressed to itself is inserted to the lower network, and discards other data. FIG. 1 shows the LLID insertion position in the MAC frame in 10G-EPON. In 10G-EPON, a field of 2 octets is secured in the preamble of the MAC frame.

In the wireless base station accommodating PON system, when the user terminal moves to the area of another base station during communication, the LLID of the ONU that accommodates the base station before the movement remains inserted in the downlink data. The ONU that accommodates the previous base station cannot receive downlink data. Therefore, it is necessary to disconnect the communication once and establish a new link. In

Patent Documents

1 and 2, since this handover is not taken into consideration, the handover cannot be executed without disconnecting the communication.

In addition, in a wireless network using a single star mobile backhaul, in order to realize soft handover, it is necessary to duplicate the same downlink data and transmit it to a plurality of base stations. Accordingly, the bandwidth used per user increases.

Therefore, an object of the present invention is to perform handover without disconnecting communication when a user terminal moves during communication in a wireless base station accommodating PON system using a PON system for a mobile backhaul. Another object of the present invention is to prevent an increase in bandwidth used per user that occurs when executing a soft handover in a normal wireless network.

A passive optical network system in which an optical transmission line termination device and a plurality of optical line termination devices are connected via an optical fiber, a wireless base station that accommodates wireless user terminals respectively connected to a plurality of ONUs, the OLT and the Internet And the optical transmission line termination device gives an LLID (Logical Link ID) to each wireless user terminal, and the optical line termination device accommodates the wireless base station accommodated by itself. When the wireless user terminal detects that the wireless user terminal has moved into the communication area, the LLID of the detected wireless user terminal is requested to the optical transmission line termination device, and the optical transmission line termination device is assigned to the user terminal. The LLID is notified to the optical network unit.

According to the present invention, in a wireless station accommodating PON system, even when a user terminal moves during communication, handover can be executed without disconnecting communication. In addition, an increase in bandwidth used per user that occurs when a single star mobile backhaul is used is prevented.

10G-EPON frame format Configuration example of a wireless base station accommodating PON system to which the present invention is applied System configuration in the first embodiment Sequence diagram in the first embodiment Base station equipment configuration ONU equipment configuration OLT configuration GW equipment configuration OLT information table 80 provided in the OLT 10 in the first embodiment ONU information table 90 provided in the ONU 30 in the first embodiment ONU information table 91 provided in the ONU 31 in the first embodiment GW information table 70 provided in GW2 in the first embodiment System configuration in the second embodiment Sequence diagram in the second embodiment OLT information table 81 provided in the OLT 10 in the second embodiment OLT information table 82 provided in the OLT 11 in the second embodiment ONU information table 92 provided in the ONU 31 in the second embodiment ONU information table 93 provided in the ONU 32 in the second embodiment GW information table 71 provided in GW2 in the second embodiment

FIG. 2 shows a configuration example of a wireless base station accommodating PON system to which the present invention is applied. This system includes an Internet 1, OLTs 10 and 11, a GW (Gate Way) 2 that connects the Internet 1 and the

OLTs

10 and 11, and

optical splitters

20 and 21 that branch optical fibers connected to the

OLTs

10 and 11. And ONUs 30, 31, 32, 33 to which optical fibers branched by the

optical splitters

20, 21 are connected, and

radio base stations

40, 41, 42, 43 accommodated by the ONUs 30, 31, 32, 33, respectively. Is done. The

radio base stations

40, 41, 42, and 43 have

communication areas

60, 61, 62, and 63, respectively, and

users

50, 51, 52, 53, 54, and 55 exist in any of the areas. .

Hereinafter, embodiments of the present invention will be described in detail with reference to examples. In addition, the same code | symbol is provided to the common part in each figure.

<First embodiment>
First, the configuration of the system in the first embodiment of the present invention will be described below with reference to FIG. In this embodiment, it is assumed that wireless LAN terminals are accommodated.

[Base Station Description]
FIG. 5 shows an apparatus diagram of the base station. The base station includes an ONU transmission / reception unit 401, a data processing unit 402, a wireless transmission / reception unit 403, and a user information unit 404.

The ONU side transceiver 401 of the base station has a function of transmitting uplink data from a wireless user to the ONU and receiving downlink data from the ONU. The radio-side transmitting / receiving unit 403 has a function of transmitting downlink data from the ONU to the destination user and receiving uplink data from the user. The data processing unit 402 includes data conversion and scheduling for transmitting and receiving uplink and downlink data, and a connection management function with a wireless terminal and ONU. The user information unit 404 holds connection information such as a connected user's MAC address and terminal ID in a user information table. When a user newly establishes a connection within the communication area of the base station's own base station, the data processing unit 402 registers the user's MAC address in the user information table of the user information unit 404, and further, for the ONU Send the MAC address notification of the same user. The MAC address notification includes a control frame identification field and a user MAC address. When the user registered in the base station moves out of the communication area of the base station, the data processing unit 402 deletes the MAC address of the user from the user information table in the user information unit 404, and the ONU A delete notification of the same user is transmitted to. The erasure notification includes a control frame identification field and a user MAC address.

[ONU explanation]
FIG. 6 shows the configuration of the ONU. The ONU includes a WDM coupler 301, a transceiver 302, a PON PHY 303, a PON MAC 304, and a radio base station IF (InterFace) 305. The WDM coupler 301 performs multiplexing / demultiplexing of the upstream and downstream optical signals. The transceiver 302 converts the upstream electrical signal input from the PON PHY 303 into an optical signal and transmits it, and also converts the downstream optical signal input from the WDM coupler 301 into an electrical signal and transmits it to the PON PHY 303 at the subsequent stage. The PON PHY 303 performs encoding and parallel / serial conversion on the uplink signal input from the PON MAC 304 and transmits the result to the transceiver 302. Also, the downlink signal input from the transceiver 302 is clock-synchronized, bit-determined, serial / parallel converted, decoded, and transmitted to the PON MAC 304. The PON MAC 304 is equipped with an upstream and downstream data processing function, MPCP (Multi Point Control Protocol) which is a control protocol of the PON system, and the like. The radio base station IF 305 is an interface for connecting a radio base station, and transmits downlink data from the PON MAC 304 to the radio base station. Also, the uplink data from the radio base station is output to the PON MAC 304.

Also, the ONU holds an ONU information table in the PON MAC 304. Each ONU information table includes the MAC address of the user terminal existing in the communication area of the accommodated base station and the LLID assigned to the OLT. When receiving the MAC address notification of the user terminal whose MAC address is not registered in the ONU information table from the accommodated base station, the PON-MAC 304 of the ONU transmits the received MAC address notification to the OLT and transmits the new user's MAC address notification. Check LLID. When the ONU PON MAC 304 receives the LLID notification of the new user from the OLT, it records both the received LLID and the MAC address of the user terminal in the ONU information table. The LLID notification includes a control frame identification field, a user MAC address, and a user LLID.

Upon receiving the user deletion notification from the base station, the ONU PON MAC 304 deletes the item corresponding to the MAC address included in the user deletion notification from the ONU information table of the PON MAC 304, and further the PON MAC 304 notifies the OLT to the user deletion notification. Send.

When the ONU receives the uplink data from the base station, the ONU adds the LLID held in the ONU information table of the PON MAC 304 to the uplink data and transmits it to the OLT at the time allocated to the OLT.

When the ONU receives the downlink data from the OLT, the ONU refers to the LLID of the downlink data received by the PON MAC 304, and when the LLID is registered in the ONU information table, the ONU receives the downlink data received by the accommodating base station. Send. Downlink data in which an LLID in which the LLID is not registered in the ONU information table is inserted is discarded.

When the ONU sends a MAC address notification or erasure notification from the PON MAC 304 to the OLT, the ONU inserts the LLID given to the ONU into the control frame.

[OLT explanation]
FIG. 7 shows the configuration of the OLT. The OLT includes a WDM coupler 101, a transceiver 102, a PON PHY 103, a PON MAC 104, and an NNI (Network-Network Interface) 105. The WDM coupler 101 performs multiplexing / demultiplexing of upstream and downstream optical signals. The transceiver 102 converts the downstream electrical signal input from the PON PHY 103 into an optical signal and transmits it, and also converts the downstream optical signal input from the WDM coupler 101 into an electrical signal and transmits it to the PON PHY 103 at the subsequent stage. The PON PHY 103 performs encoding and parallel / serial conversion on the downlink signal input from the PON MAC 104 and transmits the result to the transceiver 102. The uplink signal input from the transmitter / receiver 102 is clock-synchronized, bit-determined, serial / parallel converted, decoded, and transmitted to the PON MAC 104. The PON MAC 104 is equipped with an upstream and downstream data processing function, MPCP (Multi Point Control Protocol) which is a control protocol of the PON system, and the like. The NNI 105 is an interface for connecting to the GW, and transmits uplink data from the PON MAC 104 to the GW. Also, the downlink data from the GW is output to the PON MAC 104.

The OLT holds an OLT information table in the PON MAC 104. The OLT information table includes the MAC address of the user terminal existing in the communication area of the base station accommodated by the ONU connected to the OLT, the LLID assigned by the OLT corresponding to the MAC address, and the user terminal Contains the ID of the ONU that sent the MAC address notification.

When the OLT receives the MAC address notification from the ONU, the OLT refers to the OLT information table of the PON MAC 104 and specifies whether or not the MAC address notified by the MAC address notification is already registered. When the MAC address notified by the MAC address notification is already registered, the ID of the ONU that notified the MAC address notification is added in association with the MAC address in the OLT control table. Further, the OLT transmits an LLID notification describing the corresponding LLID from the PON MAC 104 to the ONU that has transmitted the MAC address notification. On the other hand, when the MAC address notified by the MAC address notification is not registered, the MAC address notified, the MAC address notification is transmitted, and the unused LLID is converted into an OLT information table of the PON MAC 104 together with the ONU. To record. Further, when the MAC address notified by the MAC address notification is not registered, the OLT further transmits a data transmission notification of the user from the PON-MAC 104 to the GW. The data transmission notification includes a control frame identification field, a user MAC address, and an OLT ID.

When the OLT receives downlink data from the GW, the PON MAC 104 refers to the destination MAC address and the OLT information table, inserts the LLID corresponding to the destination MAC address, and transmits it to the ONU.

When the OLT receives the deletion notification from the ONU, the OLT deletes the ONU ID corresponding to the user in the OLT information table of the PON MAC 104. When all the registered ONU IDs of the corresponding user are deleted, the MAC address and LLID are also deleted from the OLT information table of the PON MAC 104. Further, the OLT transmits a data stop notification of the user from the PON MAC 104 to the GW. The data stop notification includes a control frame identification field, a user MAC address, and an OLT ID.

In addition, for upstream data from the ONU, the same operation as the normal PON system is performed.

[GW description]
FIG. 8 shows the device configuration of the GW. The GW includes an upper NW (Network) side transmission / reception unit 201, a data processing unit 202, an OLT side transmission / reception unit 203, and a GW information unit 204. The upper NW side transmission / reception unit 401 has a function of transmitting uplink data from the OLT to the Internet and receiving downlink data from the Internet. The OLT side transmitting / receiving unit 203 has a function of transmitting downlink data from the Internet to the OLT and receiving uplink data from the OLT. The data processing unit 202 has data conversion for transmitting and receiving uplink and downlink data and a connection management function with the OLT. The GW information unit 204 holds the MAC address of the user connected to the base station of the lower NW and the ID of the OLT existing above the base station to which the corresponding user is connected by the GW information table.

When the GW receives the data transmission notification from the OLT, the GW records the MAC address described in the data transmission notification and the ID of the OLT that transmitted the data transmission notification in the GW information table of the GW information unit 204.

When the GW receives downlink data from the Internet, the data processing unit 202 refers to the MAC address of the downlink data and the GW information table of the GW information unit 204, and transmits the data to the corresponding OLT.

When the GW receives the data stop notification from the OLT, the GW deletes the ID of the OLT corresponding to the MAC address included in the data stop notification from the information held in the GW information table of the GW information unit 204. As a result, transmission of data whose destination is the corresponding MAC address to the OLT is stopped. At this time, if all IDs of the OLT corresponding to the corresponding MAC address are deleted, the corresponding MAC address is deleted.

[Description of Operation of First Example] An operation when the user 50 starts communication in the area 60 and moves to the area 61 will be described with reference to FIGS. 3 and 4.

When the base station 40 detects the user 50 existing in the area 60, the base station 40 transmits a MAC address notification to the ONU 30 (S100). In the example of FIG. 3, User 50 is notified. If the MAC address included in the MAC address notification is not held in the ONU control table, the ONU 30 transmits the MAC address notification to the OLT 10 (S101).

When the OLT 10 receives the MAC address notification from the ONU, the OLT 10 refers to the OLT information table 80 shown in FIG. 9 and confirms whether the MAC address included in the MAC address notification is registered in the OLT information table 80. When the MAC address included in the MAC address notification is not registered in the OLT information table 80, the OLT gives LLID to the MAC address described in the MAC address notification. In the example of FIG. 9, since the MAC address (User50) described in the MAC address notification is not registered, the OLT 10 assigns a new LLID (ID0_50), and the MAC address (User50) and ONU ID (30). At the same time, it is recorded in the OLT control table 80. Thereby, the entry 801 of the OLT control table is created. (However, ONU IO (31) is not held here.) Then, the OLT 10 transmits an LLID notification including the newly assigned LLID (ID0_50) and the user's MAC address (User50) to the ONU 30 (S102). ). When the ONU 30 receives the LLID notification from the OLT 10, it registers the MAC address (User50) and LLID (ID0_50) in the ONU information table 90 shown in FIG. Thereby, the entry 901 of the ONU control table 90 is created. The OLT 10 transmits a data transmission notification including the user's MAC address (User50) and OLTID (10) to the GW 2 (S103). When the GW 2 receives the data transmission notification from the OLT 10, the MAC address (User 50) and the OLTOLID (10) are registered in the GW information table 70 shown in FIG. 12, and an entry 701 is created. As a result, the GW 2 transmits downlink data addressed to the user 50 to the OLT 10 (S106).

When the OLT 10 receives the downlink data from the GW 2, the OLT 10 refers to the OLT control table 80, inserts the LLID (ID0_50) into the MAC frame addressed to the user 50, and transmits it to the

ONUs

30 and 31. When the ONU 30 receives the downlink data from the OLT 10, the ONU 30 confirms whether the LLID (ID0_50) included in the downlink data is registered in the ONU information table 90. Since ONL 30 has LLID (ID0_50) registered in the ONU information table 90, the ONU 30 performs reception processing on the downlink data and transmits the downlink data subjected to the reception processing to the base station 40. The base station 40 transmits the downlink data to the user 50 (S104, S105). On the other hand, since the LLID (ID0_50) is not registered in the ONU information table 91, the ONU 31 discards the downlink data addressed to the user 50 including the LLID (ID0_50) (S105).

Thereafter, it is assumed that the user 50 moves to an area where the

areas

60 and 61 overlap and the base station 41 detects the user 50. The base station 41 transmits a MAC address notification including User50, which is the MAC address of the user 50, to the ONU 31 (S107). If the MAC address User50 is not registered in the ONU information table 91, the ONU 31 transmits the MAC address notification to the OLT 10 (S108). Since the LLID (ID0_50) corresponding to the User 50 has already been registered in the OLT information table 80, the OLT 10 transmits an LLID notification including the LLID (ID0_50) and the MAC address (User50) to the ONU 31. At this time, the OLT 10 adds the ONU ID (31) to the ONUID corresponding to the User 50 in the OLT information table 80 (S109).

The ONU 31 that has received the LLID notification from the OLT 10 registers the MAC address (User50) and LLID (ID0_50) included in the LLID notification in the ONU information table 91, and an entry 911 is created. Then, until now, the ONU 31 has discarded the data addressed to the user 50, but since the LLID (ID0_50) is registered in the ONU information table 91, the ONU 31 receives the downlink data addressed to the user 50 and sends it to the base station 41. To send. At this time, the user 50 receives data from both the base stations 40 and 41 (S110, S111, S112, S113). For this, it is assumed that the user 50's terminal receives the data with the better radio wave condition.

Next, it is assumed that the user 50 moves out of the area 60.

When the base station 40 cannot detect the user 50, the base station 40 transmits an erasure notification of the user 50 including the MAC address User50 of the user 50 to the ONU 30 (S114). When the ONU 30 receives the user deletion notification, the ONU 30 refers to the MAC address included in the user deletion notification and holds the MAC address (User50) and the MAC address (User50) of the user 50 in the ONU information table 90. Delete LLID (ID0_50). Further, the ONU 30 transmits the erasure notification to the OLT 10 (S115). When the OLT 10 receives the erasure notification, the OLT 10 refers to the MAC address User50 included in the erasure notification, and among the ONU IDs held in correspondence with the user 50 (MAC address User50) in the OLT information table 80, the erasure notification Delete the ONU ID (30) of the ONU that sent. Thereafter, the ONU 30 does not have an entry registered with the LLID (ID0_50) in the ONU information table 90, so the downlink data addressed to the user 50 is discarded, and only the ONU 31 receives the downlink data addressed to the user 50. .

Suppose further that the user 50 moves out of the area 61.

Similarly, when the base station 41 cannot detect the user 50, the base station 41 transmits an erasure notification of the user 50 to the ONU 31 (S119). The ONU 31 deletes the LLID (ID0_50) held in correspondence with the MAC address (User50) and the MAC address (User50) of the user 50 in the ONU information table 91. Further, the ONU 31 transmits the erasure notification to the OLT 10 (S120). When the OLT 10 receives the erasure notification from the ONU 31, the OLT ID (31) that is the ID of the ONU 31 that has transmitted the erasure notification from the ONUID held in correspondence with the user 50 (MAC address User50) in the OLT information table 80 is obtained. to erase. Further, the OLT 1 determines that the user 50 has moved from the lower network of the OLT 10 because the ONU ID held in correspondence with the MAC address User50 has been deleted in the OLT control table 80, and the MAC address (User50) of the user 50 is determined. ) And LLID (ID0_50) are deleted from the OLT control table 80. Thus, this LLID (ID0_50) can be used again when another user is newly registered.

At this time, the OLT 10 transmits a data stop notification of the user 50 to the GW 2 (S121). GW2, which has received the data stop notification, refers to the MAC address Use50 included in the data stop notification, and deletes the OLT ID (10) corresponding to the user 50 in the GW information table 70. Further, the GW 2 deletes the MAC address (User 50) because all the OLT IDs held corresponding to the MAC address Use 50 have been deleted in the GW control table 70. Thereafter, even if the data addressed to the user 50 is received by the GW2, it is not transmitted to the OLT10. In this way, by assigning LLID to each user and using the same ID after moving, handover can be executed without disconnecting communication in the radio base station accommodating PON system.

Further, in a general wireless system, the GW needs to acquire the location information of the user terminal and needs to be updated every time the user terminal moves. Therefore, the amount of information to be held and the message overhead can be reduced. When the present invention is applied to a wireless network such as a femtocell where the frequency of occurrence of handover is high and the number of branches of the GW lower network is large, the message overhead can be further reduced.

[Second embodiment]
Next, the system configuration in the second embodiment of the present invention will be described below with reference to FIG. In the first embodiment, the example in which the user terminal moves between base stations connected to the same OLT has been described. However, in this embodiment, the operation when moving between base stations connected to different OLTs is described. explain.

Specifically, OLT 10 and OLT 11 are connected to GW 2, ONU 31 is connected to OLT 10, and ONU 32 is connected to OLT 11. The operation when the user 52 moves from the communication area 61 of the base station 41 accommodated by the ONU 31 to the communication area 62 of the base station 42 accommodated by the ONU 32 will be described. The functions of GW, OLT, ONU, and base station are the same as those in the first embodiment. In this embodiment, it is assumed that wireless LAN terminals are accommodated.

[Explanation of operation of the second embodiment]
Here, an operation when the user 52 starts communication in the area 61 and moves to the area 62 will be described with reference to FIGS. 13 and 14.

When the base station 41 detects the user 52 existing in the area 61, a MAC address notification is transmitted to the ONU 31 (S200). The ONU 31 transmits the MAC address notification to the OLT 10 (S201). Then, the OLT 10 refers to the OLT information table 81 shown in FIG. Here, since the MAC address (User 52) described in the MAC address notification has not been registered, LLID (ID0_52) is newly assigned to the MAC address (User 52), and the MAC address is stored in the OLT information table 81. LLID (ID0_52) is recorded together with (User52) and ONU ID (31), and an entry 811 is created. Then, the LLID notification is transmitted to the ONU 31 (S202). When the ONU 31 receives the LLID notification, it registers the MAC address (User 52) and LL ID (ID0_52) in the ONU information table 92 shown in FIG. Further, the OLT 10 transmits a data transmission notification to the GW 2 (S203). When the GW 2 receives the data transmission notification from the OLT 10, the GW 2 registers the MAC address (User 52) and the OLT ID (10) included in the data transmission notification in the GW information table 71 shown in FIG. 19 and creates an entry 711. However, at this time, the OLT ID (11) is not registered. As a result, the GW 2 transmits data addressed to the user 52 to the OLT 10 (S206). The OLT 10 inserts LLID (ID0_52) into the MAC frame addressed to the user 52 and transmits it to the ONU 31. Here, since the LLID (ID0_52) is registered in the ONU information table 92, the ONU 31 receives data addressed to the user 52, transmits it to the base station 41, and transmits it to the user 52 (S204, S205).

Then, it is assumed that the user 52 moves to an area where the

areas

61 and 62 overlap and the base station 42 detects. The base station 42 transmits a MAC address notification to the ONU 32 (S207), and the ONU 32 transmits the MAC address notification to the OLT 11 (S208). Here, in the OLT control table 82 of the OLT 11 shown in FIG. 16, since the MAC address (User 52) described in the MAC address notification is unregistered, an LLID (ID1_52) is assigned, and the MAC address (User 52) and The ONU ID (32) and the newly assigned LLID (ID1_52) are recorded in the OLT control table 81 to create an entry 821. Then, the OLT 11 transmits an LLID notification to the ONU 32 (S209). When receiving the LLID notification, the ONU 32 registers the MAC address (User 52) and LL ID (ID0_52) in the ONU information table 93. Further, the OLT 11 transmits a data transmission notification to the GW 2 (S210). When the GW 2 receives the data transmission notification from the OLT 11, the GW 2 additionally registers the OLT ID (11) with the OLT ID held corresponding to the MAC address (User 52) in the GW information table 71. Thereafter, the GW 2 transmits downlink data addressed to the user 52 to both the OLTs 10 and 11 (S213, S216). The OLT 11 inserts LLID (ID1_52) into the MAC frame addressed to the user 52 and transmits it to the ONU 32. Here, since the LLID (ID1_52) is registered in the ONU information table 93, the ONU 32 receives the downlink data addressed to the user 52 and transmits the received downlink data to the base station 42. The base station 42 transmits downlink data addressed to the user 52 to the user 52 (S214, S215). At this time, different LLIDs (ID0_52 and ID1_52) are used for the same user 52, and the user 52 receives data from both the base stations 41 and 42 (S211, S212, S214, S215). However, in this case, there is no problem even if different LLIDs are used because the PON networks that transmit data are different.

Next, it is assumed that the user 52 moves out of the area 61. Then, when the base station 41 cannot detect the user 52, the base station 41 transmits a deletion notification of the user 52 to the ONU 31 (S217). The ONU 31 deletes the MAC address (User 52) and LLID (ID0_52) of the user 52 in the ONU information table 92, and transmits the deletion notification to the OLT 10 (S218). The OLT 10 erases the ONU ID (31) of the user 52 in the OLT information table 81. Furthermore, since all ONU ID registrations have been deleted, the OLT 10 determines that the user 52 has moved out of the lower network of the OLT 10 and deletes the MAC address (User52) and LLID (ID0_52) of the user 52 from the OLT information table 81. Then, the data stop notification of the user 52 is transmitted to the GW 2 (S219). The GW 2 receiving the data stop notification deletes the OLT ID (10) corresponding to the user 52 in the GW information table 71. Thereafter, data is transmitted to the user 52 only via the OLT 11 and the ONU 32 (S220, S221).

Suppose further that the user 52 has moved outside the area 62. Then, similarly, since the base station 42 can no longer detect the user 52, the deletion notification of the user 52 is transmitted to the ONU 32 (S223). The ONU 32 deletes the MAC address (User52) and LLID (ID1_52) of the user 52 in the information table 93, and transmits the deletion notification to the OLT 11 (S224). The OLT 11 deletes the ONU ID (32) of the user 52 in the OLT information table 82. Further, since all ONU ID registrations have been deleted, the OLT 11 determines that the user 50 has moved out of the jurisdiction of the OLT 10 and deletes the user 50's MAC address (User52) and LLID (ID1_52) from the OLT information table 82. . Further, the OLT 11 transmits a data stop notification of the user 52 to the GW 2 (S225). The GW 2 that has received the data stop notification deletes the OLT ID (11) corresponding to the user 52 in the GW information table 71, and further deletes the MAC address (User 52) because no OLT ID has been registered. Thereafter, even if the data addressed to the user 52 is received by the GW2, it is not transmitted to the

OLTs

10 and 11.

By executing such an operation, even when moving between base stations connected to different OLTs, handover can be executed without disconnecting communication.

[Other]
Each of the above-described embodiments is a preferred embodiment of the present invention, and can be modified within a range that does not depart from the gist of the present invention. For example, in the first and second embodiments, the MAC address is used as the terminal identifier, but there is no problem even if the terminal ID is used.

1 Internet 2 GW
10, 11 OLT
20, 21

Optical splitter

30, 31, 32, 33 ONU
40, 41, 42, 43

Base station

50, 51, 52, 53, 54, 55 User terminal 70 GW information table 80, 81, 82 OLT information table 90, 91 ONU information table 101 WDM coupler 102 Transceiver 103 PON PHY
104 PON MAC
105 NNI
201 Upper NW side transceiver unit 202 Data processing unit 203 OLT side transceiver unit 204 GW information unit 301 WDM coupler 302 Transceiver 303 PON PHY
304 PON MAC
305 Radio base station IF
401 ONU side transmission / reception unit 402 Data processing unit 403 Wireless side transmission /

reception units

701, 711, 801, 811, 821, 901, 911, 921, 931 entries

Claims

A passive optical network system in which an optical transmission line termination device and a plurality of optical line termination devices are connected via an optical fiber;
A radio base station that accommodates radio user terminals respectively connected to a plurality of ONUs;
A gateway for connecting the OLT and the Internet,
The optical transmission line termination device gives an LLID (Logical Link ID) to each wireless user terminal,
When the optical line termination device detects that a wireless user terminal has moved into the communication area of the wireless base station accommodated by itself, the optical line termination device transmits the detected LLID of the wireless user terminal to the optical transmission line termination device. To request and
The optical transmission line termination device notifies the optical line termination device of the LLID assigned to the user terminal.
In the PON system according to claim 1,
The optical line terminator is:
An optical line terminator information table that holds the correspondence between the identifier of the wireless user terminal existing in the communication area of the radio base station connected to the optical line terminator and the LLID assigned to the user terminal. Hold and
With reference to the LLID included in the downlink data received from the optical transmission line termination device, whether the LLID is registered in the optical line termination device information table or not, the optical base station receives the optical transmission line termination device. A PON system that determines whether or not to transmit downlink data received from a PON.
In the PON system according to claim 2,
The optical line terminator is:
When a wireless user terminal that is not registered in the optical line termination device information table is detected within the communication area of the wireless base station connected to the optical line termination device, the corresponding optical user terminal A PON system that transmits a wireless terminal identifier notification that notifies an identifier.
In the PON system according to claim 3,
The optical line terminator is:
When a wireless user terminal registered in the optical line terminator information table moves out of a communication area of a radio base station connected to the optical line terminator, the corresponding wireless user is retrieved from the optical line terminator information table. A PON system that deletes terminal information and transmits an erasure notification that notifies the transmission line termination device of movement of the corresponding wireless user terminal.
In the PON system according to claim 4,
The optical transmission line termination device is:
The identifier of the wireless user terminal, LLID, and the wireless base station with which the user is communicating are present in the communication area of the wireless base station accommodated by the optical line terminating device connected to the optical transmission line terminating device. Holds an optical transmission line terminator information table that records the correspondence with the identifier of the connected optical line terminator,
Referring to the identifier of the wireless user terminal included in the downlink data received from the communication control device, the LLID associated with the identifier of the wireless user terminal in the optical transmission line termination device information table is assigned to the downlink data. A PON system that transmits the downlink data to an optical line termination device.
In the PON system according to claim 3,
The optical transmission line termination device is:
The identifier of the wireless user terminal, LLID, and the wireless base station with which the user is communicating are present in the communication area of the wireless base station accommodated by the optical line terminating device connected to the optical transmission line terminating device. Holds an optical transmission line terminator information table that records the correspondence with the identifier of the connected optical line terminator,
When the wireless user terminal identifier notification is received from the connected optical line terminator, the optical user terminal identifier described in the wireless user terminal identifier notification is unregistered with reference to the optical transmission line terminal device information table In this case, an LLID that is not assigned to another optical transmission line termination device is assigned in association with the wireless user terminal identifier, and the LLID together with the wireless user terminal identifier and the identifier of the optical line termination device is added to the optical transmission line termination device. A PON system that registers in a device information table, notifies the optical line termination device of the LLID, and transmits a data transmission notification requesting data transmission of the corresponding wireless user terminal to the communication control device.
In the PON system according to claim 6,
The optical transmission line termination device is:
When the wireless user terminal identifier notification is received from the connected optical line terminal device, the wireless user terminal identifier included in the wireless user terminal identifier notification has been registered with reference to the optical transmission line terminal device information table In this case, the identifier of the optical line terminator is additionally registered in association with the LLID registered in association with the radio user terminal identifier and the corresponding LLID is notified to the optical line terminator. PON system characterized by
In the PON system according to claim 4,
The optical transmission line termination device is:
When the erasure notification is received from the connected optical line terminator, the optical transmission line terminator information table is referred to, and the identifier of the optical line terminator corresponding to the wireless user terminal identifier included in the erasure notice is deleted. When the identifier of the optical line terminal device corresponding to the wireless user terminal identifier is lost, a data stop notification is transmitted to the communication control device, and the stop of data transmission addressed to the user is requested. system.
In the PON system according to claim 6,
The communication control device includes:
Holding a communication control device information table that records information on the wireless user terminal identifier of the wireless user terminal connected at the lower level and the identifier of the optical transmission line termination device on the communication path of the wireless user terminal;
When the data transmission notification is received from the connected optical transmission line termination device, the identifier of the optical transmission line termination device is registered together with the wireless user terminal identifier of the corresponding wireless user terminal in the communication control device information table. PON system to do.
In the PON system according to claim 8,
The communication control device includes:
Holding a communication control device information table that records information on the wireless user terminal identifier of the wireless user terminal connected at the lower level and the identifier of the optical transmission line termination device on the communication path of the wireless user terminal;
When the data stop notification is received from the connected optical transmission line termination device, the identifier of the optical transmission line termination device that transmitted the data stop notification is deleted from the identifier of the optical transmission line termination device corresponding to the corresponding wireless user terminal identifier. A PON system characterized by
An optical transmission line termination device and an optical line termination device connected to a radio base station accommodating a wireless user terminal,
The optical line terminator is:
Upon detecting that the wireless user terminal has moved within the communication area of the wireless base station accommodated by the own device, the LLID of the detected wireless user terminal is requested to the optical transmission line termination device,
Determining whether or not to forward downlink data received from the optical transmission line termination device to a wireless base station, based on an LLID assigned to each wireless user terminal notified from the optical transmission line termination device; Optical line terminator.
In the optical line termination device according to claim 11,
An optical line terminator information table that holds the correspondence between the identifier of the wireless user terminal existing in the communication area of the radio base station connected to the optical line terminator and the LLID assigned to the user terminal. Hold and
With reference to the LLID included in the downlink data received from the optical transmission line termination device, whether the LLID is registered in the optical line termination device information table or not, the optical base station receives the optical transmission line termination device. An optical line termination device that determines whether or not to transmit downlink data received from the network.
An optical transmission line terminating device connected to an optical line terminating device connected to a wireless base station that accommodates wireless user terminals,
The optical transmission line termination device is:
When an LLID notification including a wireless user terminal identifier is received from the optical line termination device, an LLID is assigned to each wireless user terminal, and the assigned LLID is notified to the optical line termination device. apparatus.
The optical transmission line termination device according to claim 13, further connected to a communication control device,
The identifier of the wireless user terminal, LLID, and the wireless base station with which the user is communicating are present in the communication area of the wireless base station accommodated by the optical line terminating device connected to the optical transmission line terminating device. Holds an optical transmission line terminator information table that records the correspondence with the identifier of the connected optical line terminator,
Referring to the identifier of the wireless user terminal included in the downlink data received from the communication control device, the LLID associated with the identifier of the wireless user terminal in the optical transmission line termination device information table is assigned to the downlink data. An optical transmission line terminating device that transmits the downlink data to an optical line terminating device.
In the optical transmission line termination device according to claim 14,
The identifier of the wireless user terminal, LLID, and the wireless base station with which the user is communicating are present in the communication area of the wireless base station accommodated by the optical line terminating device connected to the optical transmission line terminating device. Holds an optical transmission line terminator information table that records the correspondence with the identifier of the connected optical line terminator,
When a wireless user terminal identifier notification is received from the connected optical line terminal device, the wireless user terminal identifier described in the wireless user terminal identifier notification is unregistered with reference to the optical transmission line terminal device information table A LLID not assigned to another optical transmission line termination device is assigned in association with the wireless user terminal identifier, and the LLID together with the wireless user terminal identifier and the identifier of the optical line termination device is assigned to the optical transmission line termination device. An optical transmission line termination device which registers in an information table, notifies the optical line termination device of the LLID, and transmits a data transmission notification requesting data transmission of the corresponding wireless user terminal to the communication control device.
In the optical transmission line termination device according to claim 15,
The optical transmission line termination device is:
When the wireless user terminal identifier notification is received from the connected optical line terminal device, the wireless user terminal identifier included in the wireless user terminal identifier notification has been registered with reference to the optical transmission line terminal device information table In this case, the identifier of the optical line terminator is additionally registered in association with the LLID registered in association with the radio user terminal identifier and the corresponding LLID is notified to the optical line terminator. An optical transmission line termination device.