Wireless network load generator address mask manipulation

• US 20050135244A1
• Filed: 12/15/2004
• Published: 06/23/2005
• Est. Priority Date: 12/19/2003
• Status: Abandoned Application

• Current Assignee: Ixia (Keysight Technologies, Inc.)
• Original Assignee: Communication Machinery Corp. (Keysight Technologies, Inc.)
• Inventors: Miller, Douglas M., Balmy, Ken, Bechdol, Jeff A.
• Application Number:
  US11/013,524
• Publication Number:
  US 20050135244A1
• Time in Patent Office: Days
• US Class Current: 370/229
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 61/35 involving non-standard use of addresses for implementing network functionalities, e.g. coding subscription information within the address or functional addressing, i.e. assigning an address to a function
• CPC Class Codes: H04L 63/0236 Filtering by address, protocol, port number or service, e.g. IP-address or URL
• CPC Class Codes: H04L 69/14 Multichannel or multilink protocols
• CPC Class Codes: H04W 12/088 using filters or firewalls
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A method and system for using a single wireless network interface to selectively accept for further processing frames transmitted in a wireless data communications network. This allows a host system to emulate the operation of multiple, concurrently active stations in the wireless network. All wireless stations so emulated adhere to the requirements of applicable standard protocols; particularly, in the context of this innovation, with respect to contention for use of the communications medium and acceptance for further processing of frames transmitted on the medium to an emulated station from a communicating peer station. Each emulated station is assigned a unique address in accordance with the applicable standard protocol, which satisfies the characteristics of a programmable, masking address filter. The address filter allows the interface to accept frames addressed to a conforming emulated wireless station while ignoring other frames. This technique is useful in the creation of efficient systems which may thereby provide interface to the wireless medium concurrently on behalf of multiple emulated stations, giving the appearance from the network standpoint of multiple wireless stations which are all in fact operated within a single device.

Claims

1. A method of so operating a wireless communication system which has a plurality of emulated wireless stations that only transmitted data frames addressed to one of the emulated stations will be received, this method comprising the steps of:

providing a host system which has a plurality of virtual wireless stations and the capability of receiving data frames transmitted to the host system from a communication peer station;

applying to all transmitted data frames received at the host system an address filter with the capability of identifying a receiver address embedded in each of the transmitted data frames;

comparing the identified data frame address with a base address of the host system; and

accepting into the host system only those data frames with identified addresses that match the base address of the host system.

2. A method as defined in claim 1 wherein:

the address filter is programmed with a binary mask value;

the binary mask value is applied in a logic AND operation to the incoming frame receiver address in each incoming frame; and

the value derived from the AND operation is compared to a match value.

3. A method as defined in claim 2 in which the match value is the result obtained by applying the binary mask value in a logic AND operation to the host system base address.

4. A method as defined in claim 1 which comprises the step of programming the address filter at initialization of the host system.

5. A method as defined in claim 1 which includes the step of changing the binary mask value in the address filter.

6. A method as defined in claim 1 in which the host system base address and the address mask values are expressed as a string of hexadecimal digits.

7. A method as defined in claim 1 in which the address filter comprises a binary address mask value and address matching criteria.

8. A method as defined in claim 7 in which:

the binary value of the address mask is used to select address bits for subsequent comparison;

address bits in each bit position where the corresponding bit in the address mask has the value 1 are used in the comparison; and

address bits in each bit position where the corresponding bit in the address mask has the value 0 are ignored in the comparison.

9. A method as defined in claim 7 in which:

the AND operation is performed in a bitwise manner to apply the binary value of the address mask to the binary value of an address and produce a masked address value for comparison with another masked address value;

each bit position in which both the address operand and the address mask operand have the value 1 produces the value 1 in that bit position of the masked address value comparison result; and

each bit position in which either the address operand or the address mask operand has the value 0 produces the value 0 in that bit position of the masked address value comparison result.

10. A wireless communication host system which comprises:

a plurality of emulated wireless stations, each of those stations having the capability of accepting data addressed to it in a frame transmitted from a peer station to the host system; and

an address filter for rejecting all data frames which;

(a) are transmitted from the peer station to the host system but (b) are not addressed to a virtual station of the host system.

11. A wireless communication system as defined in claim 10 which has a transmitting protocol subsystem and a receiving protocol subsystem for transmitting data frames to and receiving data frames from a communicating peer station.

12. A wireless communication system as defined in claim 10 in which:

the address filter comprises a base address and an address mask and the capability of;

so combining the base address and the address mask as to generate a base address value of the system;

so combining the receiver address of an incoming data frame and the address mask as to generate an incoming frame receiver address value; and

so comparing the system base address value and the incoming frame receiver address as to determine if the two values are equal and the incoming data frame is to accordingly be accepted by the host system.

13. A system as defined in claim 10 in which the address filter comprises a binary mask value and address matching criteria.