KR100223984B1 - Mac frame structure of wireless communication protocol - Google Patents

Abstract

The present invention provides a frame control area, a duration / ID area, a first address area, a second address area, a third address area, and a sequence control to facilitate communication between systems using different types of protocols. A wireless communication implemented by including a type area for storing information for distinguishing types of other protocols to be matched in a MAC frame structure of a protocol including an area, a fourth address area, a frame body area, and a seed area. This is a description of the MAC frame structure of the protocol.

Description

MAC frame structure of wireless communication protocol

1 is a diagram showing a conventional mac frame structure.

2 is a view showing the frame structure of the Mac according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Frame Control Area 2: Duration / ID Area

3: first address area 4: second address area

5: third address area 6: sequence control area

7: fourth address area 8: frame body area

9: seed area 10: type area

The present invention is to apply information to the header of the existing MAC frame (Media Access Control: MAC frame) in order to solve the problem that occurs when implementing the system by applying the protocol specification of the IEEE 802 committee as it is. It also relates to the Mac frame structure.

Although the present invention has not yet been confirmed as a complete protocol as of October 1995, the invention is based on the IEEE 802.11 protocol drafted in March 1995, and the full name of the document is as follows.

IEEE P802. 11

Wireless Access Method and Physical Layer Specification

Proposed text for section 11

Based on responses to Draft D1 Letter Ballot

processed at March 1995 Meeting.

SUMMARY OF THE INVENTION The present invention is a method for solving a problem occurring when matching a wired LAN and a wireless LAN, and an object thereof is to add an item not considered or overlooked by an IEEE 802 committee to a MAC (802.11) header. .

In particular, the emphasis was on interworking between a network based on carrier sense multiple access / collision detection (CSMA / CD) and 802.11, a carrier sense multiple access / collision avoidance (CSMA / CA) network.

The CSMA / CD network protocols, IEEE 802.3 and Ethernet, have a similar frame but a completely different structure. Therefore, when different frames are delivered to a wireless station through an access point (AP), the wireless station cannot operate correctly because there is no field to distinguish them in the IEEE 802.11 specification.

If this information is added to any field, there will be no interoperability and communication with other vendors' Network Interface Cards (NICs) and access points will not be possible. In addition, if the IEEE 802.11 specification is left intact, no protocol other than the first protocol can be used.

However, the MAC frame structure of the conventional IEEE 802.11 has a 2-byte frame control region 1 and a 2-byte duration / ID region 2 as shown in FIG. And a six-byte first address region 3, a six-byte second address region 4, a six-byte third address region 5, and a two-byte sequence control region 6 ), A six-byte fourth address region 7, a 2313-byte frame body region 8, and a 4-byte CRC region 9.

As shown in FIG. 1, the existing IEEE 802.11 protocol does not have an area for distinguishing between other protocols and Ethernet or 802.3, and thus there is a problem in that there is no compatibility when performing communication between different protocols. have.

Accordingly, in the present invention, in order to solve the problem of the conventional MAC frame structure, a new MAC frame structure is added to the existing 802.11 frame structure by adding a type field having a value equal to a length of 802.3 and a type field of Ethernet. Implemented

FIG. 2 shows a new MAC frame structure implemented by the present invention, which is matched between the fourth address region 7 and the frame body region 8 in the MAC frame structure of the existing protocol shown in FIG. The structure includes a type region 10 capable of determining the type of protocol.

Looking at the communication process in the protocol having a MAC frame structure of the second diagram as follows.

First, when communication is performed outbound, i.e., wired LAN → access point → wireless station, the access point receives the frame of the wired LAN and analyzes the frame to determine the third field (type, length) of the wired Mac. Save it. When the received frame goes to the wireless station, the frame is made into an 802.11 frame and then delivered to the wireless station. The MAC header of the wireless station tells the upper protocol stack where the actual data begins, based on the type field value.

On the contrary, when communication is performed in an inbound state, i.e., a wireless station → an access point → a wired LAN, the upper protocol of the wireless station informs the wireless MAC (802.11 MAC) of the type of protocol. The wireless MAC adds a value specifying the type of the protocol to the type region 10 on the 802.11 frame and delivers it to the access point as in the present invention.

The access point sends a frame to the wired LAN after determining the third field of the wired MAC according to the value added to the type region 10.

If the MAC frame according to the present invention having the structure as shown in FIG. 2 is implemented as a frame of the IEEE 802.11 protocol, IEEE 802.3, which is a network of CSMA / CD, and IEEE 802.11, which is a network of CSMA / CA, can be smoothly interworked. You get an effect.

In addition, when wired / wireless LAN is matched, a smooth communication between a server of a wired LAN and a station of a wireless LAN can be achieved, and various protocol specifications can be supported.

Claims (2)

A frame control area, a duration / id area, a first address area, a second address area, a third address area, a sequence control area, a fourth address area, a frame body area, and a seed area A MAC frame structure of a wireless communication protocol, comprising: a MAC frame structure of a protocol to include a type area for storing information for distinguishing types of other protocols matched during communication. 2. The MAC frame structure of a wireless communication protocol according to claim 1, wherein 2 bytes are allocated to the type region.