Method and device address management

• US 20050141515A1
• Filed: 12/10/2004
• Published: 06/30/2005
• Est. Priority Date: 12/19/2003
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Rollet, Romain, Mangin, Christophe
• Granted Patent: US 7,805,538 B2
• Time in Patent Office: Days
• US Class Current: 370/395.500
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 61/10 of different types
• CPC Class Codes: H04L 61/5038 for local use, e.g. in LAN or USB networks, or in a controller area network [CAN]
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation

Abstract

There is disclosed a method and a device of address management in a network (10) which comprises a plurality of devices, comprising at least one STAtion (STA), and at least one Address Resource Management (ARM) unit. Each of the devices includes a stack of communication protocol layers comprising at least an Upper Layer (UL) and a Lower Layer (LL). The UL of each of the devices has a respective UL address (14) within the network. The ARM unit associates, respectively disassociates, some of the devices in at least one LL network (11). The devices of a given LL network are allowed to exchange together data packets emitted and received at the LL level. The ARM unit allocates, respectively releases, one given LL address (15) per each associated device, respectively disassociated device, in a given LL network. Besides, the ARM unit handles one ARM Translation Table (TT) per LL network. The TT comprises one entry per device of a given LL network and each entry comprises the UL address and the LL address.

Claims

1. A method of Address Management in a network which comprises a plurality of devices, comprising at least one STAtion (STA), and at least one Address Resource Management (ARM) unit, wherein each of the devices includes a stack of communication protocol layers comprising at least an Upper Layer (UL) and a Lower Layer (LL), the UL of each of said devices having a respective UL address within the network, said method comprising the following steps of:

associating, respectively disassociating, some of said devices in at least one LL network, which devices being allowed to exchange together data packets emitted and received at the LL level, said associating including the devices sending their UL address to the ARM unit;

allocating, respectively releasing, one given LL address per UL address of each one of said devices which are associated, respectively disassociated, in a given LL network, said allocating being carried out by the ARM unit; and

handling one ARM Translation Table (TT) per LL network, said TT comprising one entry per device of a given LL network, which entry comprising said UL address and said LL address, said handling being carried out by the ARM unit.

2. The method of claim 1, wherein the ARM TT comprises at least the following information for each device of the LL network:

the UL address of said device;

the LL address of said device; and

an operational status of said device.

3. The method of claim 2, wherein the ARM unit performs the step of allocating an LL address by handling a Free Address List, which includes LL addresses available for allocation to respective devices to be associated in the corresponding LL network, and wherein said handling comprises selecting one LL address in said Free Address List each time an address allocation is performed, and removing said selected LL address from said Free Address List, each LL address allocated to a respective device within the corresponding LL network being unique within that LL network.

4. The method of claim 3, wherein each device associated in a given LL network performs an address conversion between an LL address and a UL address through an Address Management protocol defining messages exchanged with the corresponding at least one ARM unit.

5. The method of claim 4, wherein the Address Management protocol comprises the following messages:

a Lower Layer Address Request (LLAR) message sent by any device to the ARM unit, said LLAR message comprising a specified UL address in order to request the corresponding LL address;

an Upper Layer Address Request (ULAR) message sent by any device to the ARM unit, said ULAR message comprising a specified LL address in order to request the corresponding UL address; and

an Address Relation Indication (ARI) message sent by the ARM unit in response to either said LLAR message or said ULAR message, said ARI message comprising the UL address and the LL address, respectively sent or requested via said LLAR message or said ULAR message.

6. The method of claim 5, wherein, in order to disassociate a given device from the LL network it belongs to, the corresponding ARM unit performs the steps of:

removing the corresponding entry from the ARM TT;

including the corresponding LL address in the Free Address List; and

transmitting an ARI message to all devices associated in said LL network with said LL address and with the corresponding UL address marked as invalid.

7. The method of claim 6, wherein the step of removing is preceded by the following steps:

setting the operational status of the entry in the ARM TT corresponding to the removed device with a “

defunct”

value

waiting for a predetermined time, which has been defined for this entry.

8. The method of any one of claims 5 to 7, wherein the step of allocating an LL address to a given device in a given LL network comprises the steps of:

selecting an LL address in the Free Address List;

removing said selected LL address from the Free Address List;

creating a new entry in the ARM TT with said UL address, its corresponding said selected LL address and the operational status set to a “

normal”

value; and

transmitting an ARI message comprising the UL address and said selected LL address.

9. The method of claims 5 to 8, wherein the ARM unit performs the address conversion by performing the following steps:

receiving an LLAR message, or a ULAR message, from an associated device, said message comprising an LL address, respectively a UL address;

scanning all the entries in the ARM TT in order to retrieve the UL address, respectively the LL address, which corresponds to the received LL address, respectively UL address; and

transmitting an ARI message to all the associated devices, which message includes said LL address and said UL address.

10. The method of any one of claims 5 to 9, wherein each ARI message is broadcast to all associated devices in a given LL network by the corresponding at least one ARM unit.

11. The method of any one of claims 5 to 10, wherein the ARM unit marks as invalid the UL address, respectively the LL address, in the corresponding ARI message if the LL address received via a ULAR message, respectively the UL address received via an LLAR message, does not correspond to a valid entry in its ARM TT.

12. The method of any one of claims 5 to 11, wherein the LL comprises an Address Conversion Control Sub-Layer (ACC-SL) and a Lower Sub-Layer (L-SL), said ACC-SL performing an address conversion between an LL address and a UL address within a given LL network.

13. The method of claim 12, wherein the UL transfers a UL Protocol Data Unit (PDU) to the LL, said UL-PDU being received in said LL first by the ACC-SL, which adds then an ACC-PDU header of variable length to said UL PDU to form an ACC-PDU before transferring said ACC-PDU to the L-SL.

14. The method of claim 13, wherein the ACC-PDU header comprises an ACC-PDU type field only, or further comprises a source UL address field and/or a destination UL address field, depending on the value included in the ACC-PDU type field.

15. The method of any one of claim 13 or 14, wherein, for each UL-PDU transferred to the ACC-SL, the UL provides the ACC-SL with the source UL address and the destination UL address as parameters, and then for each ACC-PDU transferred to the L-SL, the ACC-SL provides the L-SL with the source LL address and the destination LL address as parameters.

16. The method of claim 15, wherein the ACC-SL retrieves the destination LL address by performing an address conversion from the destination UL address received as parameter.

17. The method of claim 15 or 16, wherein each STA handles a STA Translation Table (STA TT) permanently comprising at least two following entries:

its own UL and LL addresses; and

a UL broadcast address and an LL broadcast address, which are used for transmitting broadcast messages.

18. The method of claim 17, wherein the STA TT further comprises one entry per device the STA is able to communicate with, each entry including the following information:

the corresponding LL and UL addresses; and

a Location field, which contains “

internal”

or “

external”

value, depending on whether the corresponding device is internal or external to the considered LL network, respectively.

19. The method of claim 17 or 18, wherein the STA TT is updated by the corresponding ACC-SL on reception of the ARI messages only, said update comprising the steps of:

checking whether an entry corresponding to the LL address received in the ARI message is already present in the STA TT, and

if not, creating the corresponding entry and starting a corresponding timer,

else, checking if the received UL address is valid and is the same address as this included in the STA TT as corresponding to said LL address,

if not, removing the corresponding entry and discarding all data packets which are intended for the device corresponding to said removed entry,

else re-starting said timer;

and wherein an entry is removed on the expiration of said timer.

20. The method of claims 17 to 19, wherein the ACC-SL of a given STA retrieves the destination LL address from the destination UL address received as parameter, either locally by scanning its STA TT if the required LL address is present, or via the Address Management protocol according to claim 9 by performing the following steps if no entry in the STA TT corresponds to the required address:

transmitting to the ARM unit an LLAR message with the UL address received from the UL as the source UL address parameter;

receiving from the ARM unit an ARI message with said UL address and the corresponding requested LL address.

21. The method of claim 20, wherein the ACC-SL of a STA adds an ACC-PDU header to a UL-PDU to form an ACC-PDU to be transferred to the L-SL, said ACC-PDU header solely comprising the ACC-PDU type field if the destination device is internal within the same LL network as said STA, or further comprising the destination UL address filled in the destination UL address field if the destination device is external to the considering LL network.

22. The method of claim 20 or 21, wherein the ACC-SL of a STA adds an ACC-PDU header to a UL-PDU to form an ACC-PDU to be transferred to the L-SL and broadcast, said ACC-PDU header comprising its own UL address as the source UL address field.

23. The method of any one of claims 13 to 22, wherein the L-SL provides the ACC-SL with the source LL address and the destination LL address as parameters for each ACC-PDU transferred to the ACC-SL, and then the ACC-SL provides the UL with the source UL address and the destination UL address as parameters for each ACC-PDU transferred to the UL.

24. The method of claim 23, wherein the source UL address is selectively retrieved by the ACC-SL based on the value of the ACC-PDU type field, either by retrieving it from the ACC-PDU header of the received ACC-PDU if the source UL address is comprised in said ACC-PDU header, or by retrieving it from the source LL address.

25. The method of any one of claims 17 to 24, wherein the ACC-SL of a given STA retrieves a source UL address from a source LL address either locally by scanning its STA TT if the required UL address is present, or else via the Address Management protocol according to claim 9 by performing the following steps:

transmitting to the ARM unit a ULAR message with the LL address being the source UL address parameter;

receiving from the ARM unit an ARI message with said LL address and the corresponding requested UL address.

26. The method of any one of claims 17 to 25, wherein the ACC-SL of a given STA retrieves a destination UL address from one of the permanent entries in STA TT, in accordance with the destination LL address received as parameter.

27. The method of any one of claims 13 to 26, wherein the network comprises several LL networks, and at least one ARM unit per LL network, and wherein each LL network comprises at least one STA and at least one GateWay (GW) as an interconnection device allowing a data packet transmission through all LL networks in the network, said GW belonging to at least two LL networks with one LL address per LL network it belongs to, and inter-connecting the devices comprised in those LL networks it belongs to.

28. The method of claim 27, wherein an entry in the ARM TT corresponding to a GW belonging to the corresponding LL network is extended with the list of UL addresses of those devices not belonging to said LL network which are managed by said GW.

29. The method of claim 27 or 28, wherein the ARM unit uses, in the ARM TT, a given GW entry as a default entry when a UL address does not match any ARM TT entry, the list of UL addresses corresponding to said GW entry being empty.

30. The method of any claims 27 to 29, wherein the ARI message comprises the LL address of the GW, when the UL address corresponds to a device belonging to an LL network, other than the LL network which comprises the ARM unit, and interconnected through said GW.

31. The method of any one of claims 27 to 30, wherein an ARI message further comprises a location information which indicates whether the device corresponding to the addresses exchanged with the ARM unit through the ULAR and/or the LLAR messages, is a device belonging to the same LL network as said ARM unit, or a device belonging to another LL network interconnected through a GW device.

32. The method of any one of claims 27 to 31, wherein each GW handles a GW Translation Table (GW TT) per LL network it belongs to, said GW TT permanently comprising at least the following entry:

a UL broadcast address and an LL broadcast address used for transmitting broadcast messages.

33. The method of claim 32, wherein a GW further handles in the UL a Relaying Table in order to select the GW TT corresponding to the destination LL network of a received PDU to be transmitted.

34. The method of claim 32 or 33, wherein the GW TT further comprises one entry per device associated in the corresponding LL network STA is able to communicate with, which entry includes the following fields:

the corresponding LL and UL addresses.

35. The method of any one of claims 32 to 34, wherein the GW TT is updated by the corresponding ACC-SL only on reception of the ARI messages according to the following steps:

checking whether an entry corresponding to the LL address received in the ARI message is already present in the GW TT

if not, creating the corresponding entry and starting a corresponding timer is started,

else, checking if the received UL address is valid and is the same address as this included in the GW TT as corresponding to said LL address,

if not, removing the corresponding entry,

else, the timer corresponding to the valid entry is re-started,

and wherein an entry is removed from the GW TT on expiration of said timer.

36. The method of any one of claims 27 to 35, wherein the ACC-SL of a GW processes an ACC-PDU, transferred by the L-SL, only if its ACC-PDU header includes the destination UL address in its destination UL address field.

37. The method of claim 36, wherein the ACC-SL of the GW processes only an ACC-PDU with an ACC-PDU header including at least the source UL address field filled in with the source UL address when the destination LL address is a broadcast address.

38. The method of claim 36 or 37, wherein the ACC-SL of a given GW retrieves a source UL address from a source LL address either locally by scanning its GW TT if the required UL address is present via the Address Management protocol according to claim 9 by performing the following steps:

transmitting to the ARM unit a ULAR message with the LL address being the source UL address parameter;

receiving from the ARM unit an ARI message with said LL address and the corresponding requested UL address.

39. The method of any one of claims 36 to 38, wherein the ACC-SL of a GW adds an ACC-PDU header to a UL-PDU to form an ACC-PDU to be transferred to the L-SL, said ACC-PDU header comprising at least the source UL address field including the source UL address.

40. The method of any one of claims 36 to 39, wherein the ACC-SL of a given GW retrieves the destination LL address from the UL address received as parameter, either locally by scanning its corresponding GW TT if the required LL address is present, or via the Address Management protocol according to claim 9 by performing the following steps if no entry in said GW TT corresponds to the required address:

transmitting to the ARM unit an LLAR message with the UL address received from the UL as the source UL address parameter;

receiving from the ARM unit an ARI message with said UL address and the corresponding requested LL address.

41. The method of any one of the preceding claims, wherein the network comprises at least two LL networks, a first LL network supporting a communication protocol A and a second LL network supporting a communication protocol B, both communication protocols being different.

42. Address management device for use in a network comprising a plurality of devices, comprising at least one STAtion (STA), and at least one Address Resource Management (ARM) unit, wherein each of said devices includes a stack of communication protocol layers comprising at least an Upper Layer (UL) and a Lower Layer (LL), said UL of each of said devices having a respective UL address within the network, said devices comprising means for carrying out a method of any one of claims 1 through 41.