Hierarchical Wireless Access System and Access Point Management Unit in the System

• US 20110141895A1
• Filed: 07/03/2008
• Published: 06/16/2011
• Est. Priority Date: 07/03/2008
• Status: Active Grant

• Current Assignee: ZTE Corporation
• Original Assignee: ZTE Corporation
• Inventors: Zhang, Shizhuang
• Granted Patent: US 8,553,729 B2
• Time in Patent Office: Days
• US Class Current: 370/235
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 28/10 Flow control between communication endpoints
• CPC Class Codes: H04W 84/16 WPBX [Wireless Private Branch Exchange]
• CPC Class Codes: H04W 88/085 Access point devices with remote components
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

A hierarchical wireless access system includes terminals, access points, centralized access gateways and a plurality of master access point management units located at the access layer and adopting distributed architecture. The master access point management unit includes a communication interface interacting with the centralized access gateway and/or core networks, to which one or more access points are attached. The master access point management unit processes forwards the data and signaling among the attached access points, and provides the function of access gateway and local operation maintenance and network management. Construction of the master access point management unit and the access point in the system is also provided.

Claims

1. A hierarchical wireless access system including terminals, access points, centralized access gateways, and further including a plurality of master access point management units located at an access layer and adopting a distributed architecture, wherein the master access point management units respectively have communication interfaces interacting with the centralized access gateways and/or core networks, to which one or more access points are attached, and the master access point management units are for processing and forwarding data and signaling interaction among the attached access points, and providing functions of access gateway, local operation and maintenance and network management for the attached access points.

2. The wireless access system according to claim 1, wherein the access gateway function of the master access point management unit is realized by an access gateway functional module AGW-Lite thereof, which is used for converging access information of attached access points and processing tunnel protocols, providing routing switching information to a corresponding centralized access gateway, providing communication interfaces to interact with the centralized access gateways and/or core networks, and realizing one of the following functions:

local wireless resource processing, self-routing for local flows, ending processing for tunnel processing of attached access points, flow shaping and flow control on attached access points and data stream scheduling processing based on access points.

3. The wireless access system according to claim 1, wherein the wireless access system further including one or more slave access point management units, which are connected with the master access point management units directly or after being cascaded, part of the access points attached to master access point management units connected with one slave access point management unit are attached to the slave access point management unit to process and forward data and signaling interaction among the attached access points;

master access point management units and slave access point management units which are directly connected with the access points have a power-line modulation and demodulation function, and adopt the power line as a transmission medium to directly connect with the attached access points; and

a communication cable is used as a transmission medium between the master access point management unit and the slave access point access point management unit.

4. The wireless access system according to claim 1, wherein the master access point management unit is connected with its attached access points directly or via a switch;

and

a communication cable is used as a transmission medium between the master access point management unit and the access points directly connected with the master access point management unit;

or the master access point management unit has a power-line modulation and demodulation function, and the power line is used as a transmission medium between the master access point management unit and the access points that are directly connected with the master access point management unit.

6. The wireless access system according to claim 3, wherein the master access point management units, or the master access point management units and the slave master access point management units, include timing servers for generating timing information and distributing the information to each attached access point;

and

the access point includes a timing client for receiving and restoring the timing information and taking the restored timing information as a local reference timing signal.

7. The wireless access system according to claim 6, wherein the timing server is a timing over packet server, namely, a ToP server, and the timing client is a timing over packet client, namely, a ToP client;

the ToP server is used for generating a hardware timestamp according to a reference timing signal output by a GPS receiving module or an external synchronous clock source and distributing the hardware timestamp in the form of a ToP information packet to each ToP client via network interfaces on the access point management unit side and the access point side; and

after receiving the timing information packet, the ToP client restores the timing information and sends the restored information to a baseband and radio frequency module in the access points.

8. The wireless access system according to claim 3, wherein the wireless access system is applied to a scene of indoor coverage or a scene of mixed indoor coverage and outdoor coverage.

9. The wireless access system according to claim 8, wherein the wireless access system is an access service network of a WiMAX system, the access point is a Pico base station Pico BS;

the centralized access gateway is an access service to network gateway ASN-GW; and

the master access point management unit interacts with the ASN-GW and/or network elements of a connection service network via the access gateway functional module.

10. The wireless access system according to claim 9, wherein in the wireless access system a standard R6 interface is used between the master access point management unit and the Pico BS, or between the master access point management unit or the Pico BS and the slave access point management unit;

a standard R3 interface is used between the master access point management unit and a network element of the connection service network; and

a standard R4 interface is used between master access point management units and between the master access point management unit and the centralized access gateway.

11. The wireless access system according to claim 1, wherein the wireless access system further including one or more couplers or power dividers taking the access points as signal sources, and a passive distributed antenna system connected with the couplers or power dividers.

12. The wireless access system according to claim 1, wherein the wireless access system adopts a PUSC (Partially Used Sub-channel) ALL Sub-Channel networking mode;

or

the wireless access system adopts a PUSC Segment networking mode;

or

the wireless access system adopts the PUSC Segment networking mode in a coverage-limited area and uses the PUSC ALL Sub-Channel networking mode in other areas.

13. The wireless access system according to claim 1, wherein the wireless access system combines multiple physically separated access points into a logical cell group, in which access points share different sub-channels of the same channel;

different logical cell groups are distributed with different channels; and

the master access point management unit distributes sub-channels according to location relations among the access points subordinate to the logical cell groups.

14. The wireless access system according to claim 4, further including one or more couplers, which couple three-phase currents of one transformer.

5. (canceled)

15. An access point management unit in a hierarchical wireless access system, the hierarchical wireless access system including the access point management unit located at an access layer and access points attached to the access point management unit;

the access point management unit at least including;

a master control switching module, having a communication interface interacting with access points attached to the access point management unit is realized, for processing and forwarding data and signaling interaction of the access points attached to the access point management unit; and

a timing server for distributing clock information to timing clients of access points attached to the access point management unit via the master control switching module.

16. The access point management unit according to claim 15, wherein the access point management unit is a slave access point management unit, and the master control switching module further has a communication interface connected to a master access point management unit or another slave access point management unit.

17. The access point management unit according to claim 15, wherein the access point management unit is a master access point management unit integrated with an access gateway functional module which is for converging access information of access points attached to the master access point management unit, processing tunnel protocols, providing routing switching information to a corresponding centralized access gateway, providing communication interfaces interacting with core networks, and realizing one of the following functions:

local wireless resource processing, self-routing for local flows, ending processing for tunnel processing of attached access points, flow shaping and flow control on attached access points and data stream scheduling processing based on access points.

18. The access point management unit according to claim 17, wherein the master access point management unit further includes a centralized network management functional module which is connected with the master control switching to module to realize a centralized agent function on local network management and to process operation maintenance information, including one or more of the following:

performance statistics, alarm management, version management, configuration management and fault diagnosis.

19. The access point management unit according to claim 15, wherein the timing server is a timing over packet server, namely, a ToP server, which is for generating a hardware timestamp according to a reference timing signal output by a GPS receiving module or an external synchronous clock source, and distributing the hardware timestamp to a ToP client of the attached access point via a ToP information packet.

20. The access point management unit according to claim 15, further including a clock source, which is connected with the timing server to output a reference timing signal to the timing server.

21. The access point management unit according to claim 15, further including a power line modulation demodulation functional module, which is connected with the master control switching module and connected to an access point via a power line to modulate and demodulate signals transmitted by the power line and to perform a link detection and/or adaptive processing.

22. An access point in a hierarchical wireless access system adopting power line transmission, including a timing client, which includes a configuration information storage unit, a timing signal restoration unit, a timing state determination unit and a scheduling control unit, wherein

the configuration information storage unit is used for storing multiple configured timing states and corresponding scheduling mode information, and determination condition information of each timing state related to timing precision;

the timing signal restoration unit is used for restoring a timing signal according to a received timing information packet, outputting the restored timing signal to a baseband and radio frequency module, and at the same time, outputting a convergence condition of a timing algorithm to the timing state determination unit;

to the timing state determination unit is used for determining the current timing precision according to the convergence condition of the timing algorithm, determining the current timing state according to the configured timing state determination condition and outputting the determined timing state to the scheduling control unit; and

the scheduling control unit is used for determining a corresponding scheduling mode according to the current timing state and carrying out uplink scheduling and downlink scheduling.

23. The access point according to claim 22, wherein the timing state stored in the configuration information storage unit includes a locked state, a free oscillation state and an intermediate state, wherein the timing precision corresponding to the intermediate state is between that corresponding to the locked state and that corresponding to the free oscillation state;

and

the scheduling mode corresponding to the locked state stored in the configuration information storage unit refers to normal uplink scheduling and normal downlink scheduling;

the scheduling mode corresponding to the intermediate state includes;

marking the last or multiple symbols of an uplink as a unavailable state; and

the scheduling mode corresponding to the free oscillation state includes;

turning off a transceiver.