Method and device for connection of a device to a wireless network

The present invention relates to a first device for connecting a second device to a network and a method thereof. The present invention is particularly applicable to networks that require device registration to determine a medium access control address, such as IEEE 802.11 type networks.

FIG. 1 shows, for example, a wireless subnetwork 11 that is connected to, for example, a wired medium subnetwork 12 that complies with the IEEE802.3 (Ethernet®) standard, and that complies with, for example, the IEEE802.11 standard. .. This wireless subnetworks includes a large number of stations (13-16), one of which has the function of an access point (AP). The access point gives access to distributed system services to other stations that must be associated with the access point. The access point of FIG. 1 further includes a portal from the wireless subnet to the distributed medium (not shown) and a portal from the distributed medium to the wired subnet 12. This allows stations on the wireless subnet network to exchange data frames with devices 17-19. It should be noted that this is not the only possible embodiment.

A station that is not an access point cannot host a portal for connecting to another subnetwork. When a device such as a personal computer is connected to a station via, for example, an Ethernet® connection, the device is not recognized as being on a wireless network. One possible solution is to have the device control the configuration and management of the station so that it is substantially a device with station functionality. For example, it is possible to use specific software to control a station from a device via a device-to-station link, which requires specific software and allows multiple devices to be on the same station. It makes it more difficult to connect.

<p> It is an object of the present invention to provide a method of connecting a device to a wireless network.</p><p> It is an object of the present invention to further provide a bridge device adapted for communication on a wireless network and connection of a first device having no wireless communication function.</p>

<p> The methods of the invention are at the level of bridging devices adapted to interface with wireless networks. -The stage of detecting the connection between the device and the bridge device, and -The stage of determining the address of the device and the address of the bridging device, and -It is characterized in that the bridging device includes a step of separately registering the device and the bridging device as a wireless device on a wireless network using each address.</p><p> According to one embodiment, the address is the unique MAC address of the device and is generally determined at the time of manufacture.</p><p> According to one embodiment, the method of the present invention comprises having a bridging device monitor traffic on a wireless network for the device.</p><p> According to one embodiment, the method of the present invention is for programming a packet filter for a packet having a device address as a destination address, and when detecting such a packet, receiving the packet on behalf of the device. It further includes the stage of acknowledging.</p><p> According to one embodiment, the method of the invention -The stage of forwarding all multicast packets detected on the wireless network from the bridging device to the connected device, -The stage of forwarding all broadcast packets detected on the wireless network from the bridging device to the connected device, -Including at least one step of forwarding a unicast packet on a wireless network to the device, which has the address of the connected device as the destination address.</p><p> According to one embodiment, the connection between the device and the bridge device is an Ethernet® connection, and the step of detecting the connection is to use a previously unknown source address of the Ethernet® device. Includes the step of monitoring packets on an Ethernet® connection for detection.</p><p> According to one embodiment, the wireless network is of the IEEE 802.11 type, and the methods of the invention further step in maintaining a single management information base for both the bridge device and the connected device. Including.</p><p> The bridging device of the present invention -Means to determine the addresses of the first and bridge devices, -Includes means to perform two separate device registrations on the wireless network, one for the bridge device and one for the first device, using their respective addresses.</p>

Other features of the invention are shown in the description of non-limiting examples of the invention. These examples will be described with reference to the following drawings.

As shown in FIG. 2, the network of the embodiment of the present invention is connected to an IEEE802.11 compliant wireless subnetwork 21 via an access point 26 and conforms to IEEE802.3 (Ethernet®). Includes Wired Subnetwork 22. The wireless subnetwork 21 includes three stations 23, 27, and 28 in addition to the access point 26. The station 23 refers to a "wireless box" or "box", in which the other device, which is the device 24 (eg, a personal computer or a household device such as an audio / video receiver), is transferred to the wireless subnet 21. Indicates the specific function to connect.

According to an embodiment of the present invention, the connection between the device 24 and the wireless box 23 is an Ethernet® link. Note that this connection may be different, for example, based on USB or based on an IEEE802.x standard other than Ethernet®.

Both device 24 and wireless box 23 have independent TCP / IP / HTTP protocol stacks. The advantage of having an independent protocol stack at the level of the wireless box is that any device connected to the wireless box can control the wireless box using a standard internet browser. According to an embodiment of the present invention, the device 24 has a fixed MAC address, and the wireless box also has a fixed MAC address.

According to the embodiments of the present invention, these separate MAC addresses are used by the device 24 and the wireless box 23 on the wireless medium. From the perspective of wireless subnetworks, it looks as if there are two stations. The station that incorporates the wireless box emulates two stations. That is, one station represents a wireless box and the other station represents device 24. The station in which the wireless box is installed associates with the access point once using each MAC address, twice in total.

In IEEE 802.11 networks, MAC addresses are used for a number of purposes. Many purposes include: -Specific MAC sublayer management entity ("MLME") behavior (eg, association, authentication, labor saving ...), the access point communicates and registers with the station using the station's MAC address; -The user control plane protocol (for example, the MAC address is embedded in the MAC packet data unit ("PDU"), and the station that detects the MAC address in the destination address field of the packet tells the source device. Must generate acknowledgment packet) As shown in FIG. 3, the wireless box 23, along with other circuits, provides a microprocessor 41 for executing at least some of the protocols 42, 43 required to control the wireless box and interface with each medium. Including. The corresponding data is stored in memory 44. Some 802.11 protocols can be run using dedicated hardware instead of software run by a microprocessor. In general, a large number of associations and subsequent management of several parallel user data flows corresponding to different MAC addresses are handled by software, while dedicated hardware is the MAC address of the packet on the wireless network. Detects and manages the generation of acknowledgment packets. The dedicated MAC hardware is referred to as IEEE802.11MAC-HW, and the MAC software is referred to as IEEE802.11MAC-SW. The TCP / IP / HTTP stack sits on top of the MAC layer.

FIG. 4 is a time series diagram of the messages exchanged with the access point 26 for authentication and association of the wireless box 23 and the device 24 as stations. The same process applies when one or more devices are connected to the wireless box 23.

During the setup phase, the wireless box first registers with the access point via the authentication and association process determined by the IEEE 802.11 standard. The wireless box uses its MAC address for this exchange.

The wireless box then initiates the registration process for device 24. This process can be triggered, for example, by detecting an Ethernet® packet on bus 25 by a wireless box. This packet contains a previously unknown MAC source address. This registration process is the same as the process for registering a wireless box. The wireless box programs its IEEE 802.11-HW to separate packets with both MAC addresses.

The wireless box behaves as if it represents two stations, which may be more than one, depending on the number of devices connected to the link. Therefore, a wireless box may have to perform a particular task twice, while some tasks or resources may be common to all of the stations represented by the wireless box.

FIG. 5 is a diagram showing the MAC layer structure of a wireless box on an IEEE 802.11 interface.

At the top layer of the stack is the Logical Link Control (LLC) layer, which manages the bridging function of the wireless box. The MAC sublayer management entity (ie, "MLME") provides a layer management service interface through which layer management primitives can be invoked. The delivery module component provides an interface to any component that requires the services of the IEEE802.11 MAC layer. The delivery module component routes frames, maintains a map of associated stations (BSS) and / or authenticated stations (IBSS), and each logical FIFO (if the wireless box acts as an access point). Manages one for the associated station) and feeds the frame to the MAC driver. The delivery module also manages the formation of a "traffic instruction map", or "TIM", that the driver uses to generate the beacon (again, if the wireless box is an access point). Finally, the station management entity (SME) manages the activation of MLME and physical layer management entities (PLME -not shown) primitives. This entity is a device when information should be exchanged with the outside world, for example when the user sets up a wireless box (the user can, for example, connect a personal computer to the network and set certain parameters). -Provides an interface to the remote configurator (not shown). SME manages the collection of layer-dependent state data from various layer management entities and the setting of layer-specific parameter values (MIB attributes, MIB stands for Management Information Base). .. That is, the SME manages the configuration of the station.

According to the embodiments of the present invention, there is only one MIB for the wireless box and the device connected to the wireless box. This suggests that the same encryption key is used for both the wireless box and the device. The power management mode is also the same.

According to a modification of the examples of the present invention, not all MIB parameters are the same. For example, different encryption keys can be used.

However, a remote network manager (eg, a personal computer running a web browser) may see as many MIBs as there are MAC addresses. However, the parameters and statistics that can be set are the same. The wireless box as a station can be set up remotely from a device, another station, or a device installed on the LAN to which the access point is connected.

As mentioned above, authentication and association is done for both the wireless box and the device 24. The same is true for "join" procedures, which are used to synchronize stations to the BBS (Basic Service Set) specified in IEEE 802.11.

Two modes can be used by the station to access the medium. One is the DCF mode (distributed coordination function mode), and the other is the PCF mode (point coordination function mode). DCF mode relies on a CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) mechanism and uses a random backoff time if the medium is busy. PCF mode uses a point coordinator to manage access to the medium.

The transmission of packets in DCF mode will be described first.

IEEE802.11MAC-HW performs the same DCF algorithm for device 24 and wireless box. Use only one transmit FIFO for both the wireless box and device 24 (despite one FIFO for DCF mode and another FIFO for PCF mode). When IEEE802.11MAC-HW gains access to a medium, it sends a packet from the FIFO without giving any conditions to the source. While there is one transmission FIFO, various buffers are assigned to each of the device 24 and the wireless box. The FIFO matrix receives data from the buffer. The algorithm followed in doing this is not the object of the present invention.

The reception of packets in the DCF mode will be described below.

Upon detecting / receiving a unicast packet with the device or station MAC address, IEEE802.11MAC-HW acknowledges the packet. If the packet is a management packet, the packet is sent to the MLME section of IEEE802.11MAC-SW. In addition, when the packet is a data packet, the packet is sent to the IEEE802.11MAC-SW delivery module section. Unicast packets are the only packets that are acknowledged.

The IEEE802.11MAC-SW also maintains a list of multicast addresses for groups of which the wireless box is a member. Incoming multicast packets addressed to one of these groups are forwarded to the appropriate application in the wireless box. The wireless box software cannot know if device 24 is part of one or more multicast groups, and what the address of that group is, unless a proprietary mechanism is introduced. Therefore, the wireless box forwards all multicast packets to device 24.

Broadcast packets are forwarded to both the wireless box and the device.

Packet transmission in PCF mode will be described below.

According to the PCF mode option, the point coordinator polls the stations one at a time, allowing the stations to send packets in response to the poll. This option is called "contention-free polling" or "cf-polling". If the wireless box performs only one transmission FIFO for both the wireless box and device 24, then only one of the wireless box and device is cf-polled. In this case, according to the embodiment of the present invention, priority is given to the device connected to the wireless box. That is, the packet from the device, not the packet from the wireless box, is placed in the FIFO. If two (or more) buffers are available, both the device and the wireless box can be cf-polled.

As mentioned above, one or more devices may be connected to the wireless box. If only one PCF transmission buffer is executed by the hardware, only one device can be cf-polled. According to the embodiments of the present invention, the first device associated with the access point is optionally selected as the cf-polled device. If several buffers are available, these buffers are optionally allocated in the order of device association.

According to the embodiments of the present invention, the wireless box can be configured to initiate an independent BSS (IBSS). If there is no device connected to the wireless box, a beacon will be sent using the MAC address of the wireless box. If there is one device to be connected, the MAC address of that device is used. When one or more devices are connected, for example, the MAC address of the first associated device is used.

In the above-described embodiment, an example in which one device is connected to a wireless box is mainly used, but the present invention is not limited to this case and can be extended to any number of devices. Is. Furthermore, the invention is not limited to connecting an IEEE 802.11 network to an Ethernet® network. Other types of networks can also be connected using the present invention.

<figref num="1">It is a schematic diagram which shows the network of the prior art.</figref><figref num="2">It is a schematic diagram which shows the network including the apparatus according to the Example of this invention.</figref><figref num="3">It is a block diagram which shows the wireless box apparatus according to the Example of this invention.</figref><figref num="4">It is a figure which shows the exchange of a message at the time of obtaining two MAC addresses from an access point by the apparatus by the Example of this invention.</figref><figref num="5">It is a figure which shows the protocol layer of the IEEE802.11 stack of a wireless box.</figref>

Code description

11 Wireless subnetworks 12 Wired media subnetwork 13, 14, 15, 16 stations 16 stations (access points) 17, 18, 19 equipment 21 Wireless Subnetwork 22 Wired subnetwork 23 stations 24 equipment 25 Ethernet® Bus 26 access points 27 stations 28 stations 41 microprocessor 42 802.3 stack 43 802.11 stack 44 memory