PROTOCOL ACCELERATOR MODULE WITH PACKET FORWARDING FUNCTION AND A METHOD OF TRANSCEIVER OPERATION FOR RAPID FORWARDING OF DATA PACKETS

• US 20120002669A1
• Filed: 03/16/2010
• Published: 01/05/2012
• Est. Priority Date: 03/24/2009
• Status: Active Grant

• Current Assignee: IHP GmbH-Innovations For High Performance Microelectronics/Leibniz-Institut Fur Innovative Mikroelektronik
• Original Assignee: IHP GmbH-Innovations For High Performance Microelectronics/Leibniz-Institut Fur Innovative Mikroelektronik
• Inventors: Dietterle, Daniel, Langendörfer, Peter
• Granted Patent: US 8,654,764 B2
• Time in Patent Office: Days
• US Class Current: 370/389
• CPC Class Codes: H04L 12/417 with deterministic access, e.g. token passing
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

The present invention relates to a protocol accelerator module for a data transmission protocol level of a transceiver, particularly but not exclusively for rapid forwarding of data packets in wireless sensor networks using the time-division multiple access method according to the IEEE 802.15.4 standard. The invention also relates to a method of transceiver operation for rapid forwarding of data packets, likewise particularly, but not exclusively, in wireless sensor networks using the time-division multiple access method according to the IEEE 802.15.4 standard. The core of the invention is a reference table which stores references from identifiers of second transceivers to identifiers of third transceivers as well as references from specific messages to identifiers of third transceivers. A transceiver can check during reception of a data packet whether it is a data packet to be forwarded, and can take appropriate precautions for rapid sending of a data packet to be forwarded. This allows real-time conditions of many applications to be met.

Claims

1. A protocol accelerator module, referred to in the following as an accelerator module, for a transceiver, said transceiver being configured to forward a data packet from a second transceiver to one or more third transceivers according to a TDMA-based data transmission protocol, said accelerator module being configured

to query a reference table on receiving the data packet from the second transceiver during a first time slot, said reference table containing at least one reference from the following group of reference types:

a) a reference in a specific reception time slot to an identifier of at least one third transceiver, according to which a data packet received by the transceiver during the specific reception time slot is to be forwarded to the third transceiver;

b) a reference in an identifier of a specific second transceiver, as transmitter, to an identifier of at least one third transceiver as the predetermined receiver of the data packet, referred to in the following as a virtual connection;

or

c) a reference in a predetermined message contained in the data packet to an identifier of at least one third transceiver as the predetermined receiver of the data packet;

and when a reference corresponding to the data packet is present, to detect in the reference table an identifier of a third transceiver as the receiver of the data packet; and

during a second time slot immediately following the first time slot to cause the data packet to be sent to the third transceiver if the second time slot has been assigned to said transceiver.

2. The accelerator module of claim 1, configured to detect a receiver identifier, contained in the received data packet, of at least one third transceiver when the data packet from the second transceiver is received during the first time slot, and to cause the data packet to be sent to the third transceiver during the second time slot if no matching reference type for the data packet is present in the reference table and the second time slot has been assigned to said transceiver.

3. The accelerator module of claim 1, said accelerator module being implemented in hardware comprising

a data packet analyzer (210) on the receiver side, configured to

write payload data of the received data packet into a data payload memory (230) of the accelerator module and

to write into an information memory (250) the detected identifier of the third transceiver as the receiver of the data packet, and a memory address of the stored data payload;

and further comprising a control unit (240) on the transmitter side, configured to

receive time slot information (216) about a time slot assigned to the transceiver (200);

detect a receiver identifier of a third transceiver contained in the time slot information and to compare said identifier with detected receiver identifiers in the information memory (250);

when the receiver identifier contained in the time slot information matches a receiver identifier in the information memory (250), to fetch the data payload stored in the data payload memory (230) and associated with the matching receiver identifier on the basis of a memory address assigned to the matching receiver identifier and to trigger the generation of a packet header to be added to the fetched data payload; and

to provide the fetched data payload and the generated packet header to a transmitter unit (260) of the transceiver (200) as a data packet to be forwarded, for transmission in the assigned time slot.

4. The accelerator module of claim 1, in which a respective level of priority is assigned to a respective reference type and the accelerator module is configured to cause the data packet corresponding to the reference type of highest priority to be sent to the third transceiver when a plurality of references of different reference types matching the received data packet are simultaneously present.

5. The accelerator module of claim 1, which is configured to

assign a respective maximum retention time to specific virtual connections in the reference table;

and

to transmit received data packets which are to be forwarded according to a specific virtual connection, with prioritization according to a respective remaining retention time.

6. The accelerator module of claim 1, configured to perform tasks of a data transmission protocol according to the IEEE 802.15.4 standard in a transceiver.

7. A transceiver with an accelerator module according to claim 1.

8. The transceiver of claim 7, configured to

write a data packet destined for the transceiver into a buffer on a receiver side of the transceiver;

to manage a queue of data packets to be sent in a buffer on a transmitter side of the transceiver; and

to select data packets from the queue during a time slot assigned to the transceiver and to cause said data packets to be sent to one or more third transceivers.

9. Sensor nodes comprising a sensor, and connected thereto the transceiver of claim 7.

10. A method of transceiver operation, comprising the forwarding of a data packet from a second transceiver to one or more third transceivers according to a TDMA-based data transmission protocol, said forwarding comprising the following steps:

receiving the data packet from the second transceiver during a first time slot;

querying a reference table, said reference table containing at least one reference from the following group of reference types;

a) a reference in a specific reception time slot to an identifier of at least one third transceiver, according to which a data packet received by the transceiver during the specific reception time slot is to be forwarded to the third transceiver;

b) a reference in an identifier of a specific second transceiver, as transmitter, to an identifier of at least one third transceiver as the predetermined receiver of the data packet, referred to in the following as a virtual connection;

or

c) a reference in a predetermined message contained in the data packet to an identifier of at least one third transceiver as the predetermined receiver of the data packet;

detecting in the reference table an identifier of a third transceiver as the receiver of the data packet, if a matching reference for the data packet is present, or detecting an identifier of a third transceiver in the data payload of the received data packet, if no reference matching the data packet is present; and

sending the data packet to the third transceiver during a second time slot immediately following the first time slot, if the second time slot has been assigned to the transceiver.

11. The method of operation according to claim 10, configured to perform tasks of a data backup protocol level according to the IEEE 802.15.4 standard in a transceiver.