The present invention generally relates to an apparatus, a method, a computer program product and a system for connecting a mesh type network via an access device to another network.
In WLAN deployments without mesh services, client stations or end stations (STAs) must associate with an access point (AP) in order to gain access to the network. These STAs are dependent on the AP with which they are associated to communicate.
IEEE (Institute of Electrical and Electronics Engineers) standard 802.11s develops a wireless local area network (WLAN) mesh standard. With wireless mesh networks (WMNs) devices can easily interconnect. Each device works as a wireless router that forwards frames for other devices. Thus, networks can be easily deployed without an additional fixed infrastructure.
A so-called mesh network appears functionally equivalent to a broadcast Ethernet from the perspective of other networks and higher layer protocols. As an example, the mesh network may be an LAN according to the IEEE 802.11 specifications, where links and control elements forward frames among the network members. Thus, it normally appears as if all mesh points (MPs) in a mesh are directly connected at the link layer. This functionality is transparent to higher layer protocols.
A standard ‘infrastructure’ wireless local area network is a centralized network in which STAs attach to the AP which acts as a ‘master station’. This centralized topology makes network formation and initial channel selection easy. The AP is configured to start transmitting at a certain frequency channel and the STAs only need to find this channel e.g. by scanning a list of available frequencies. They can do so actively, by broadcasting probe requests on each visited channel, or passively, by listening for advertisements or beacons on each visited channel. After having visited all available channels, they will have found all APs that are in the vicinity, and can select one to associate with.
In many households, a digital subscriber line (DSL) provides high-speed Internet access. Due to economies of scale and strong competition, DSL modems often provide a rich set of features at an affordable price. They do not only integrate an Internet Protocol (IP) router but may furthermore work as print and file server and connect wireless clients via 802.11 links. Accordingly, 802.11 networks have a high penetration rate in the home. Furthermore, APs have become a commodity and can be found nearly everywhere.
Due to the current 802.11 design, the central AP manages the whole WLAN. However, APs typically do not interconnect. Each WLAN established by an AP is an independent network. For large scale coverage, APs require wired backbones that interconnect them. With WMN technology, devices can interconnect over the air. Each device becomes a wireless router that provides the frame forwarding service for other devices. To be able to operate as wireless router, a device needs special capabilities or software modules. However, many existing APs cannot be upgraded. Either the device's manufacturer considers a product to be end of life and thus product maintenance has ended or, the device's hardware limits possible implementations. Thus, a generic solution is needed that connects a WMN with one or more existing APs and thus provides the WMN with the AP's Internet connectivity.
Furthermore, duration/identity (D/ID), sequence control (SC) and frame check sequence (FCS) fields are provided, which are not discussed here for brevity and simplicity reasons. Further details can be gathered from the IEEE 802.11 specifications. A body (B) portion is provided to convey desired payload data up to a length of 2304 octets.
Each of the above addresses may have a length of 6 octets and maps on the address fields A1 to A4 depending on the “To DS” and “From DS” information of the FC field. The IEEE 802.11 standard clearly states that an address field is omitted “where the content of a field is shown as not applicable (N/A).” Solely when both bits “To DS” and “From DS” are set to “1”, four address fields appear in an 802.11 frame.
However, most of the current 802.11 APs, however, cannot operate in this bridging mode as described above. They solely serve as AP in their local infrastructure BSS.
Once AP C has received device B's frame, it analyzes the third address field for the destination address. If destined to AP C, the frame is sent to a higher layer where the IP router operates. If destined to device A, AP C relays the frame. Thus, AP C sends a frame to device A that has the “From DS” bit set to one and the “To DS” bit set to zero. The frame's address field 1 contains the Receiver Address (RA). In this case, it contains device A's address. The second address field contains the Transmitter Address (TA) that is AP C's address. The third address field contains the Source Address (SA), which equals device B's address.
With APs that can handle three addresses only, the local BSS is limited to a single wireless hop.
Since the AP C allows for the usage of three addresses only, all frames transmitted to the WMN must be destined to the device A. Without further information however, the device A cannot decide about a frame's final destination. Thus, the device A cannot forward frames to another destination in the WMN.
It is an object of the present invention to provide a more flexible approach which allows for interconnection and range extension of legacy networks.
This object is achieved by one aspect of the invention in which an apparatus for connecting a mesh type network via an access device to another network, the apparatus operating as a proxy device on behalf of at least one actual device present within the mesh type network, the apparatus comprises:
a) an interconnectivity layer configured for receiving frames from actual devices present within the mesh type network and for internally routing the received frames to at least one virtual device internally configured within the apparatus, and
b) a radio access controller configured to maintain individual connections between the apparatus and the access device on behalf of the at least one actual device of the mesh type network via the interconnectivity layer.
This object is also achieved by another aspect of the invention in which a method for connecting a mesh type network to another network via an access device, at least one network node of the mesh type network having an apparatus operating as a proxy device on behalf of at least one other network node in the mesh type network, the network comprises:
a) internally configuring at least one virtual device within the apparatus, wherein the at least one virtual device corresponds to an associated actual device present in the mesh type network;
b) receiving frames from actual devices of the mesh network into the apparatus;
c) internally forwarding the received frames from the actual devices of the mesh type network to a corresponding virtual device internally configured within the apparatus, via an interconnectivity layer within the apparatus;
d) maintaining individual connections between the apparatus and the access device by a radio access controller within the apparatus, and
e) delivering a signal received from the access device to an addressed virtual device within the apparatus.
The object is also achieved by a further aspect of the invention wherein a non-transitory computer readable medium comprising instructions for implementing a method for range extending legacy access point based mesh type networks via an access device when run on a computer device, the method comprising:
a) internally configuring at least one virtual device within a designated proxy device of the mesh type network,
b) using an interconnectivity layer in the designated proxy device of the mesh type network to maintain individual connections with the access device for at least one other device of the mesh type network,
c) receiving frames from the at least one other non-proxy device of the mesh type network,
d) internally routing, via the interconnectivity layer, the received frames from the non-proxy devices of the mesh type network to a corresponding virtual device internally configured within the mesh type network, and
e) forwarding the received frames from the virtual devices to the access device.
Accordingly, a sort of proxy mechanism is provided, that allows to integrate a legacy network with a wireless mesh network (WMN). Thereby, interconnection and range extension of e.g. legacy AP-based WLANs or similar types of networks can be achieved. Moreover, the proposed proxy mechanism does not require any changes or modifications to the access device(s) (e.g. AP). It works with any type of access device.
The proposed apparatuses, which serve as a proxy mechanism, may be implemented, for example, as processor devices, modules, chips, chip sets or circuitries provided in a network node or station. A processor may be controlled by a computer program product comprising code means for performing the steps of the claimed methods when run on a computer or processor device.
According to a first aspect, at least one virtual radio station can be provided within an apparatus serving as a proxy mechanism, wherein a radio access controller configured within the apparatus may be adapted to deliver a signal received from the access device to an addressed virtual device internally configured within the apparatus. Since a communication between the access device and virtual stations within the apparatus acting as a proxy mechanism is established, the correct destination address of an actual device within the mesh type network (MSN) can be easily detected.
According to a second aspect which can be combined with the above first aspect, the radio access controller may be adapted to serialize transmission requests if multiple entities try to transmit simultaneously. Thereby, multiple entities can transmit at the same time.
According to a third aspect which can be combined with any one or both of the above first and second aspects, at least one wireless access network interface card may be comprised for providing a connection to the access device, wherein the radio access controller may be adapted to interconnect the wireless network interface card and logical entities of the apparatus so as to establish the individual connections. This measure allows to maintain several independent connections at a time.
According to a fourth aspect which can be combined with the third aspect, at least one wireless access network interface card may share at least one of the physical layer and link layer channels. This measure saves processing resources.
Further advantageous developments are defined in the dependent claims.
The present invention will now be described based on various embodiments with reference to the accompanying drawings in which:
In the following, embodiments of the present invention are described on the basis of an exemplary wireless mesh network topology as shown in
End-user devices (such as end stations (STAs)) A, B and D to G can benefit from the ability to establish interoperable peer-to-peer wireless links with neighboring end-user devices and legacy access device AP “C” or base station sub-system (BSS) in a wireless mesh type network. Mesh points (MPs) can be quality of service (QoS) STAs that support mesh services, i.e. they participate in interoperable formation and operation of the mesh network. An MP may be collocated with one or more other entities (e.g., AP, portal, etc.). The client stations or end stations, e.g., STAs “A” and “B” of the wireless mesh type network (WMN) can associate with the access point (AP) “C” to gain access to an external network, e.g. the Internet. T.
According to a first embodiment, a proxy mechanism or functionality is provided, where a device that connects with both the wireless mesh network (WMN) and a legacy access device, access point (AP), or BSS base station sub-system (BSS) operates on behalf of all devices that are present in the WMN.
Additionally, the block diagram of
The procedure is initiated as soon as a frame is received from one of the devices of the wireless mesh type network (WMN) (e.g. one of devices “D” to “G” of
The same procedure can be applied in reverse when a frame is received via the access point (AP) from the external network 100. Here, one of the virtual stations can be selected based on the destination address provided in the frame from the access point (AP). From there, the frame can be forwarded from the proxy device “A” based on the destination address to the respective actual device of the WAN.
Furthermore, proxy device “A” also comprises the mesh point functionality MP that connects to the wireless mesh network (WMN). Proxy device “A” can instantiate a virtual station for each device of the WMN that proxy device “A” proxies. The interconnectivity layer 30 of proxy device “A” interconnects all logical and physical stations, mesh points and other functionality, and thus enables frame forwarding between the different entities and ensures frame delivery to the correct entity.
In the example of
In summary, an apparatus and method for connecting a mesh type network via an access device to another network have been described, wherein a proxy mechanism is provided in the mesh type network, that allows for interconnection and range extension of legacy access point based mesh type networks.
It is noted that the present invention is not restricted to the above embodiments and can be used for any network environment which comprises at least one central AP or access device for transmitting to or receiving from a connected network. Moreover, the designation of the entities or functions which provide the proposed proxy mechanism may be different, as long as they fulfill similar functions. The invention works even if there is only one other mesh device besides the one that works as forwarder or proxy device. Thus, even a single wireless access network interface card and a single radio device can be provided in the exemplary proxy device of
Variations to the disclosed embodiments can be understood and effected by those skilled in the art, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality of elements or steps. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program used for controlling processor to perform the claimed features may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope thereof.
Number | Date | Country | Kind |
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08163484 | Sep 2008 | EP | regional |
This application claims the benefit or priority of and describes the relationships between the following applications: wherein this application is a continuation of U.S. patent application Ser. No. 13/060,293, filed Feb. 23, 2011, which is the National Stage of International Application No. PCT/IB2009/053751, filed Aug. 27, 2009, which claims the priority of foreign application EP08163484 filed Sep. 2, 2008 all of which are incorporated herein in whole by reference.
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Number | Date | Country | |
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20140269428 A1 | Sep 2014 | US |
Number | Date | Country | |
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Parent | 13060293 | US | |
Child | 14287558 | US |