TW201442544A - Relaying device for wireless mesh network - Google Patents

Abstract

The present invention discloses a relaying device for wireless mesh network, such as a router. The relaying device includes a first wireless front end and a second wireless front end. The first wireless front end and the second wireless front end communicate with each other to facilitate data communication between a first external equipment and a second external equipment, wherein the first wireless front end wirelessly communicates with the first external equipment and the second wireless front end wirelessly communicates with the second external equipment using IEEE802.11 infrastructure mode transmission protocol. In contrast to the conventional concept, such a relay device facilitates the cost effective construction of a high speed wireless mesh network (WMN) by using infrastructure mode protocol.

Description

A relay device for forming a wireless mesh network

The present invention relates to a relay device for data communication, and more particularly to a wireless relay device such as a router. The invention also relates to a wireless backbone network for a wireless mesh network.

Wireless mesh networks (WMNs) are widely used because of their low upfront cost, flexible incremental deployment, and ease of maintenance. For example, WMN is widely used in community networks, corporate networks, video surveillance, voice communications, and local language services. Wireless mesh network architecture is often seen as the first choice to provide a cost-effective and dynamic high-bandwidth network for coverage areas. A wireless mesh network can be seen as a backbone infrastructure based specifically on wireless ad-hoc networks using the IEEE 802.11 ad-hoc protocol. Wireless mesh networks typically have more planning configuration information and provide a dynamic, cost-effective network within a certain geographic area. Instead, the ad-hoc network is arbitrarily formed when the wireless devices enter each other's communication range.

It is well known that almost all nodes in an existing wireless mesh network operate in an independent basic service group mode defined in the 802.11 standard, namely IBSS (also known as ad-hoc). Because the development of IBSS is always far behind the same 802.11 version of the infrastructure model, the performance of the existing wireless mesh network lags far behind the latest 802.11 technology.

When it is necessary to extend an existing wireless mesh network, the extension needs to operate in an IBBS mode that is compatible with existing wireless mesh network settings (IBSS mode is even set to not enable Use new technical features such as HT40). Therefore, the new technology cannot be applied to existing wireless mesh networks at all.

In addition, since most of the existing wireless mesh backbone networks adopt the IEEE802.11 a/g/n standard and use the ad-hoc protocol to use the 54 Mbps transmission rate, the network throughput will be reduced to less than 54 Mbps. Therefore, the work of wireless network ad hoc routing protocols focuses on scalable coupling or looking for high quality paths in the event of lossy wireless links.

Although the infrastructure model of the 802.11n standard has been in use for many years, there is no real 802.11n-based wireless mesh network on the market, which has led to an unnecessary reduction in the performance of the wireless mesh network.

Therefore, it would be highly advantageous to provide a relay device that can reduce the above known drawbacks for WMN.

The present invention provides a relay device for forming a wireless mesh network, the relay device including a first wireless front end and a second wireless front end, the first wireless front end and the second wireless front end communicate with each other to implement the first external device and The data communication between the second external device, wherein the wireless communication between the first wireless front end and the first external device and the wireless communication between the second wireless front end and the second external device adopt an IEEE 802.11 infrastructure mode transmission protocol.

It is advantageous for the wireless relay device to have first and second wireless front ends for wireless communication with the external device through the infrastructure mode, as this facilitates the construction of the wireless mesh network backbone using the infrastructure mode. That is to say, the wireless router on the backbone will use the infrastructure mode protocol for inter-route communication. The use of infrastructure mode protocols for inter-route communication is contrary to the standards or established conventions used in wireless mesh networks, but with great advantages Potential, because whenever the infrastructure agreement standard is upgraded, the network using the infrastructure mode protocol can respond immediately, so there is no need to wait for the corresponding ‘ad hoc’ protocol. Moreover, the transmission speed under the current infrastructure mode agreement is six times that of the wireless mesh network using the 'ad hoc' protocol on the market.

In one example, a WMN backbone network includes multiple wireless relay devices and uses the latest IEEE 802.11n infrastructure mode transmission protocol as an inter-route transmission protocol, so the WMN backbone network can support transmissions set by IEEE 802.11n. Speed, which is 300Mbps. The wireless backbone network built by wireless relay devices that are limited by the latest "ad hoc" mode transmission speed (currently 54 Mbps) has great advantages over conventional technologies. A further advantage of using the infrastructure mode transport protocol as a wireless relay device for routing or relaying inter-device transport protocols is that when a new standard is released and this standard is usually far ahead of the latest standards of "ad hoc" mode, infrastructure The model is ready to use this new standard. This also means that as soon as the new protocol standard is published, the speed of the disclosed wireless relay device can be increased and run at speeds supported by the new infrastructure mode protocol.

The use of infrastructure mode protocols as protocol for wireless routers in WMNs is contrary to traditional cognition because infrastructure mode protocols are not considered for general "multi-hop" such as WMN. In general, the infrastructure mode defined by 802.11 is used to allow one or more Wi-Fi workstations (STAs) to access a Wi-Fi access point (AP) in a single hop, and then the access point sequentially accesses the LAN backbone. Or, finally, access the Internet through an Ethernet cable. This determination of the infrastructure mode protocol is clearly incompatible with WMN operations that support multi-hop.

800‧‧‧Wireless Router

810‧‧‧First wireless front end

812‧‧‧First WiFi wireless module

814‧‧‧first antenna

820‧‧‧Second wireless front end

822‧‧‧Second WiFi wireless module

824‧‧‧second antenna

830‧‧‧Microprocessor

840‧‧‧Rigid casing

860‧‧‧ router embodiment, wireless router, mesh network adapter

870‧‧‧ router embodiment, AP-AP type wireless mesh router

880‧‧‧ router embodiment, Client-Client type wireless mesh router

890‧‧‧Wire mesh router, wireless router

The wireless router embodiment running in the WMN will be described below with reference to the accompanying drawings. Detailed description, wherein: FIG. 1 is a schematic diagram of a router applicable to a WMN network; FIG. 2 is a schematic diagram of a plurality of routers shown in FIG. 1; FIG. 3, 3A and 3B are respectively a first embodiment including a plurality of wireless routers in combination with an OSI model Schematic diagram of the architecture of the second and third WMN networks; FIG. 4 and FIG. 4A are schematic diagrams of the first and second WMN network topologies, respectively; FIG. 5 is a schematic diagram of an embodiment of the WMN application disclosed in the present invention; A data flow diagram of a 6-hop WMN.

The wireless router 800 of FIG. 1 includes a first wireless front end 810 and a second wireless front end 820. The first wireless front end 810 includes a first WiFi wireless module 812 that is coupled to the first antenna 814 and is controlled by the microprocessor 830. The second wireless front end 820 includes a second WiFi wireless module 822 that is coupled to the second antenna 824 and is also controlled by the microprocessor 830 to increase cost effectiveness.

The first wireless front end 810 and the second wireless front end 820 are connected to each other in a back-to-back fashion through a router board such that data can be transferred between the first and second wireless front ends. When the microprocessor executes an instruction stored in the memory, data received by one antenna under the control of the microprocessor can be transmitted to the surroundings via another antenna.

As a specific embodiment of the first wireless interface, the first wireless front end 810 is configured to communicate with an external wireless device through an infrastructure mode routing protocol. Similarly, as a specific embodiment of the second wireless interface, the second wireless front end 820 is adapted to communicate with an external wireless device also through an infrastructure mode routing protocol. In one embodiment 860 of the router, the first wireless front end is configured as an access point and the second wireless front end is configured as a client. On the router In another embodiment 870, both the first wireless front end and the second wireless front end are configured as access points. In another embodiment 880 of the router, both the first wireless front end and the second wireless front end are configured as clients. The names "client", "access point" and "infrastructure mode" as referred to herein are well-known names to those skilled in the art and are defined in the IEEE 802.11 standard, and are incorporated into the present invention without loss of generality. Sex.

As shown in FIG. 1, the wireless router 800 includes a first WiFi wireless module 812 configured to operate as a first wireless front end, and a second WiFi wireless module 822 configured to operate as a second wireless front end, and A microprocessor 830 is coupled to the first and second wireless front ends in a back-to-back manner to enable internal data communication between the first and second wireless front ends. The first WiFi wireless module 812 and the second WiFi wireless module 822 are respectively connected to the first antenna 814 and the second antenna 824 to implement wireless data transmission. Specifically, under the control of the microprocessor 830, the first antenna 814 is used for cooperation with the first WiFi wireless module 812 and the second antenna 824 is used for cooperation with the second WiFi wireless module 822. Wireless data communication with an external device through an infrastructure mode protocol. In order to reduce radio frequency interference, the first WiFi wireless module 812 and the second WiFi wireless module 822 operate in different frequency bands.

Microprocessor 830, or simply a CPU, includes a CPU module or router board known to those skilled in the art based on printed circuit board (PCB) peripheral circuitry. Typically, the WiFi module, CPU and peripheral circuitry, and both the first and second antennas are mounted on a rigid housing 840 for ease of placement. In the application embodiment shown in FIG. 2, wireless router 860 (shown as a mesh node in FIG. 2) is deployed in a cascade manner.

Because the first and second WiFi wireless modules are deployed in a back-to-back manner, such routers are also referred to as Back-N routers.

The embodiment of the wireless mesh network shown in Figure 3 includes a plurality of wireless routers 860 (WMR-1 and WMR-2) placed in cascade between Sender and Receiver. In this cascade network, each cascade wireless router 860 includes an access point (AP) interface and a client (Client) interface. Specifically, the access point (AP) interface of the WMR-1 is connected to the client (Client) interface of the sender Sender, and the client (Client) interface of the WMR-1 is connected to the access point (AP) interface of the WMR-2. The client interface of the WMR-2 is connected to the access point (AP) interface of the receiver Receiver to form a cascade network.

When the user intends to send data from the sender Sender to the receiver Receiver through the wireless mesh network, the sender Sender will become the client in the 802.11 infrastructure mode, and the sender Sender will use the 802.11 protocol and the router WMR- The access point (AP) interface of 1 establishes a data connection. When the sender Sender accesses the access point (AP) interface of the router WMR-1, a multi-hop Wi-Fi connection is established between the sender Sender and the receiver Receiver.

In a wireless mesh network established in this manner (Back-N) as described in the present invention, each Wi-Fi interface is associated with an IP address. In the embodiment shown in FIG. 3, as a simple example, the following exemplary IP address is assigned to the Wi-Fi interface:

Suppose the sender Sender(a) sends an IP packet to the receiver Receiver(f). The destination address of this IP packet will be 103.103.103.1. When the packet is defined according to the OSI layering The application layer of the sender Sender is transmitted down to the Wi-Fi layer (or the MAC layer in the OSI), and the packet will be sent directly to the access point (AP) interface of the router WMR-1 through the infrastructure mode protocol (more Specifically, this packet will also pass through the physical layer of the receiving side of the sender. But for the sake of simplicity, we ignore the physical layer and use the Wi-Fi layer as the bottom layer of the OSI model. In the 802.11 infrastructure mode, the packet leaving the client interface of the sender Sender will enter the access point interface of the router WMR-1.

The packet is then transmitted up the OSI model of WMR-1 to the IP layer on the AP side. Note that the destination address of the packet is not itself. WMR-1 will forward the packet to the appropriate interface inside WMR-1 according to the preset routing table. The preset routing table uses the following pseudo code: If (IP==101.101.101.1 ) Send it to Application Else Send it to Client of WMR-1

Therefore, the packet will be forwarded to the WMR-1 client interface. When the packet reaches the WMR-1 client Wi-Fi interface, the packet can again be sent to the WMR-2 access point Wi-Fi interface via the infrastructure mode protocol. Similarly, the packet will be transmitted up the OSI model of WMR-2 up to the IP layer on the access side. Note that the destination address of the packet is not itself. WMR-2 will forward the packet to the appropriate interface within WMR-2 according to the following exemplary routing table: If(IP==102.102.102.1)Send it to Application Else Send it to Client of WMR-2

In this embodiment, the packet will be forwarded to the client interface of WMR-2. When the packet reaches the WMR-2 client Wi-Fi interface, the packet has no choice but to be sent to the Receiver's access point Wi-Fi interface through the infrastructure mode protocol. Because the Receiver Receiver is the destination address of the packet, according to the following routing information, the IP layer of the receiving end will accept This packet is transmitted up the packet to its application layer according to the OSI model. If(IP==103.103.103.1)Send it to Application Else Send it to the Internet

If the destination address of the packet is not 103.103.103.1, the packet will be forwarded to the interface connected to the Internet.

The wireless mesh network shown in FIG. 4 is a two-dimensional outline of the cascade WMN shown in FIG. 3, which includes a plurality of WMR-1, that is, a wireless router 860, which is a mesh network interconnection. In this two-dimensional mesh network connection deployment, the data transfer mechanism is substantially the same as that described in FIG. 3 and the above description applies as appropriate herein. In particular, the dashed line indicates that all routers interconnected by the router, that is, between WMR-1, that is, the data transmission between the wireless mesh routers 860 uses the infrastructure mode protocol.

The cascade network shown in FIG. 3A is substantially the same as that shown in FIG. 3 except that the router WMR-1 is replaced with the AP-AP type wireless mesh router 870, and the router WMR-2 is replaced with the Client-Client type wireless mesh router. 880. The data transfer mechanism in this cascade deployment is substantially the same as described in Figure 3 and the above description applies here with appropriate modifications.

The two-dimensional wireless mesh network shown in FIG. 4A includes wireless mesh routers 860, 870 and 880. The data transfer mechanism in this cascade deployment is substantially the same as described in Figure 3 and the above description applies here with appropriate modifications. In particular, the data transmission between the wireless mesh routers 860, 870, 880 is indicated by a dashed line indicating that all routers are interconnected using the infrastructure mode protocol.

The cascade network shown in FIG. 3B is substantially the same as that shown in FIG. 3 except that routers WMR-1 and WMR-2 having two Wi-Fi wireless interfaces are replaced with two virtual Wi-Fi wireless. Interface wireless mesh router 890. Although the wireless mesh router 890 has only one Wi-Fi wireless interface, the wireless router 890's single Wi-Fi wireless interface can work as both an access point and a client by using some software technologies such as multi-threading. This virtual access point and client also have their own IP address. The data transfer mechanism in this cascade deployment is substantially the same as described in Figure 3 and the above description applies here with appropriate modifications.

It should be understood that the configuration of the wireless mesh router interface is very flexible. Specifically, all Back-N compatible wireless mesh routers have 2 or more wireless interfaces (physical or virtual), and all interfaces must be configured as access points or clients.

In order to be compatible with existing "multi-hop" MWNs, the present invention provides a mesh network adapter as shown in FIG. The mesh network adapter 860 is a wireless router that can function as an existing WMN and a new WMN mid-range router running different 802.11 standards. Therefore, existing WMNs can be extended with the latest 802.11 standard without replacing any old devices.

The wireless mesh network shown in Figure 6 is similar to that shown in Figure 3 except that there are two more wireless mesh routers between the sender Sender and the receiver Receiver. The data flow from the sender Sender to the receiver Receiver shown in FIG. 6 is also similar to the data stream shown in FIG. As a simple example, assign the following exemplary IP address to the Wi-Fi interface:

Because the client interface of the Wireless Mesh Router (WMR) must be wirelessly connected to the access point interface of another Wireless Mesh Router (WMR) before sending any data through 802.11, the client interface and mesh node of the sender Sender MN1 access point interface connection. When the data is started by the client interface of the sender Sender, the data will be sent directly to the access point interface of the MN1 through the infrastructure mode WiFi. The data will be transmitted up the MN1's OSI model up to the IP layer on the access point interface side. Note that the destination address of this data is not itself. MN1 will forward the data to the appropriate interface through the wired connection inside MN1 according to the preset routing table. The preset routing table uses the following pseudo code: If (IP==1.1.1.1 )Send it to Application Else Send it to Client of MN1

Therefore, the data will be forwarded to the client interface of MN1 by using the IP routing inside MN1. The client interface of MN1 is wirelessly connected to the access point interface of MN2. When the data arrives at the client interface of MN1, it will be transmitted to the access point interface of MN2 via the infrastructure mode WiFi. Similarly, data will be transmitted up the MN2's OSI model up to the IP layer on the access point interface side. Note that the destination address of this data is not itself. MN2 will forward the data to the appropriate interface via the wired connection inside MN2 according to the following exemplary routing table: If(IP==1.1.2.1)Send it to Application ElseSend it to Client Of MN2

In this embodiment, data is forwarded to the client interface of MN2 by using IP routing inside MN2. The client interface of MN2 is wirelessly connected to the access point interface of MN3. When the data arrives at the client interface of MN2, it will be transmitted to the MN3 via the infrastructure mode WiFi. Access point interface. The data will be transmitted up the MN3's OSI model up to the IP layer on the access point interface side. Note that the destination address of this data is not itself. MN3 will forward the data to the appropriate interface via the wired connection inside MN3 according to the following exemplary routing table: If(IP==1.1.3.1)Send it to Application Else Send it to Client of MN3

Accordingly, by using the IP routing inside MN3, the data will be forwarded to the client interface of MN3. The client interface of MN3 is wirelessly connected to the access point interface of MN4. When the data arrives at the client interface of MN3, it will be transmitted to the access point interface of MN4 via the infrastructure mode WiFi. The data will be transmitted up the OSI layer of MN4 to the IP layer on the access point interface side. Note that the destination address of this data is not itself. MN4 will forward the data to the appropriate interface via the wired connection inside MN4 according to the following exemplary routing table: If(IP==1.1.4.1)Send it to Application Else Send it to Client of MN4

In this embodiment, data is forwarded to the client interface of MN4 by using IP routing inside MN4. The client interface of the MN4 is wirelessly connected to the access point interface of the Receiver. When the data arrives at the client interface of MN4, it will be transmitted to Receiver's access point interface via infrastructure mode WiFi. The data is transmitted up the Receiver's OSI model up to the IP layer on the access point interface side. Because the receiver Receiver is the destination address of this data, according to the following routing information, Receiver's IP layer will accept this data and transfer the data up to its application layer according to the OSI model.

If(IP==1.1.5.1)Send it to Application Else Send it to the Internet

If the destination address of this data is not 1.1.5.1, the data will be forwarded to the interface connected to the Internet.

When data is sent by Receiver to Sender, the data is transmitted in a similar manner. Specifically, the data is transmitted in the infrastructure mode between different routers, and is forwarded through the IP route within the same router.

The above embodiment selects a data transmission speed of 300 Mbps because this is the highest transmission speed provided by the latest WiFi standard. It should be understood that the actual data transmission speed can be any value between 54 Mbps and 300 Mbps without loss of generality. For example, the data transmission speed between routers can be set to 60Mbps, 80 Mbps, 100Mbps, 120Mbps, 150Mbps, 200Mbps, 250Mbps, 300Mbps or other. In addition, it should be understood that the maximum data transmission speed depends on the data transmission speed set by the latest WiFi standard and will exceed 300 Mbps in the future.

While the invention has been described in terms of the foregoing embodiments, those skilled in the art are For example, the various interfaces of the wireless mesh router can be flexibly configured as an access point or client, as long as the client of the router can wirelessly connect to the access point of another router and all interfaces of the router can be interconnected by IP routing. In addition, there can be any interface in a wireless mesh router. In addition, although the router is taken as an example here, the present invention is also applicable to other relay devices such as forwarding devices and switches without loss of generality.

The above described specific embodiments of the present invention are further described in detail, and are intended to be illustrative of the embodiments of the present invention. Scope of protection, where the spirit and principles of the invention Any modifications, equivalent substitutions, improvements, etc. made therein are intended to be included within the scope of the present invention.

860‧‧‧Wireless Router

Claims (10)

A relay device for forming a wireless mesh network, wherein the relay device includes a first wireless front end and a second wireless front end, and the first wireless front end and the second wireless front end communicate with each other to implement the first Data communication between the external device and the second external device, wherein wireless communication between the first wireless front end and the first external device and wireless communication between the second wireless front end and the second external device use IEEE802 .11 Infrastructure Mode Transfer Protocol. The relay device of claim 1, wherein the first wireless front end configuration operates as an access point and the second wireless front end configuration operates as a client or an access point. The relay device of claim 1, wherein the wireless front end is configured to wirelessly transmit at a speed of 150 Mbps, 300 Mbps, or more. The relay device of claim 1, wherein the first wireless front end and the second wireless front end communicate in a back-to-back manner to implement data between the first wireless front end and the second wireless front end. transmission. The relay device of claim 1, wherein the relay device is configured as a router in an infrastructure mode. A wireless mesh network, characterized in that the wireless mesh network comprises a wireless network backbone, and the wireless network backbone comprises a plurality of relay devices of claim 1 for use as a data connection. The wireless mesh network of claim 6 is characterized in that the wireless network backbone further comprises at least one relay device of claim 2 of the patent scope. A wireless mesh network comprising a plurality of wireless relay devices, wherein the wireless relay devices collectively form a wireless mesh network backbone, wherein adjacent wireless relay devices are used The IEEE 802.11 infrastructure transport protocol communicates with each other. The wireless mesh network of claim 8 is characterized in that at least one of the wireless relay devices comprises a first wireless front end and a second wireless front end, and the first wireless front end and the second wireless front end communicate with each other A data communication between the first external device and the second external device, wherein wireless communication between the first wireless front end and the first external device and wireless communication between the second wireless front end and the second external device are performed Both use the IEEE 802.11 infrastructure mode transport protocol. The wireless mesh network of claim 9 is characterized in that the first wireless front end of the at least one wireless relay device is configured as a client or an access point and the second wireless front end is configured as a client or an access point.