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US6854059B2
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Method and apparatus for medium access control in powerline communication network systems
Assignee: Lakestar Semi Inc
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Filing: 2001-06-06
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Granted: 2005-02-08
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Expires: 2021-06-06
Abstract
Abstract An inventive Medium Access Control (MAC) protocol for powerline networking systems is described. The inventive MAC protocol controls access to and use of a physical medium (power lines) in a powerline networking system. The MAC protocol method and apparatus includes a method of providing “blanking intervals” in which devices using newer versions of the protocol “clear out” earlier version devices. The use of blanking intervals greatly eases backward compatibility of the network when the protocol is upgraded with new versions. The method of using blanking intervals is closely coupled to a technique of using “beacons.” The beacons are used to propagate blanking interval information throughout the network. The beacons also include a mechanism for informing devices of the expiration of blanking information. The MAC also includes a method of establishing and maintaining “virtual circuit” connections between selected devices on the network. The virtual circuits can be established in powerline networking systems not having a central controller. A method of assigning unique Logical Network Identifiers (LNIs) to logical networks in the powerline networking system is also described. The LNIs uniquely identify each of the logical networks in the network. A means for creating, managing and distributing network encryption keys is also described. The encryption keys are used by the devices in the powerline networking system to prevent data from being shared with unauthorized users.
Inventors
- 👤 Steven Holmsen Gardner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:29
CPC Classifications
H; H04; H04L; H04L63/00; H04L63/04; H04L63/0428; H04B; H04B3/00; H04B3/54; H04B3/542; H04L63/06; H04L63/062; H04L63/08; H04L63/083; H04L9/00; H04L9/08; H04L9/0891; H04B2203/00; H04B2203/54; H04B2203/5404; H04B2203/5408; H04B2203/5429; H04B2203/5445
Claims Analysis
Total Claims: 75
Claim 1
Independent Claim
146 words
A method of performing encryption key management in an AC powerline communication network system, wherein the communication network system includes at least one receiving client device and at least one originating client device, and wherein the at least one receiving client device lacks user input capability, and wherein the at least one originating client device has user input capability, comprising the steps of: (a) inputting one of a hard-wired key and a password into the at least one originating client device; (b) creating an encryption key update payload message comprising a current network encryption key encrypted by a hard-wired key; (c) transmitting the encryption key update payload message from the at least one originating client device to the at least one receiving client device; and (d) replacing a previous network encryption key with the current network encryption key in the at least one receiving client device.
Claim 2
Independent Claim
146 words
A method of performing encryption key management in an AC powerline communication network system, wherein the communication network system includes at least one receiving client device and at least one originating client device, and wherein the at least one receiving client device lacks user input capability, and wherein the at least one originating client device has user input capability, comprising the steps of: (a) inputting one of a hard-wired key and a password into the at least one originating client device; (b) creating an encryption key update payload message comprising a current network encryption key encrypted by a hard-wired key; (c) transmitting the encryption key update payload message from the at least one originating client device to the at least one receiving client device; and (d) replacing a previous network encryption key with the current network encryption key in the at least one receiving client device.
Claim 3
Dependent Claim
103 words
The method of performing encryption key management as set forth in claim 1 , further comprising the steps of: (e) creating a key update acknowledgement payload message comprising the hard-wired key encrypted by the current network encryption key; (f) transmitting the key update acknowledgement payload message from the at least one receiving client device to the at least one originating client device; and (g) re-transmitting the encryption key update payload message transmitted in sub-step (c) of claim 1 until the at least one originating client device receives the key update acknowledgment payload message from the at least one receiving client device, then terminating.
Claim 4
Dependent Claim
48 words
The method of performing encryption key management as set forth in claim 1 , wherein the inputting step (a) comprises the sub-steps of: (1) selecting an encryption key algorithm; and (2) inputting one of a hard-wired key and a password into the at least one originating client device.
Claim 5
Dependent Claim
21 words
The method of performing encryption key management of claim 3 , wherein the encryption key algorithm is a Data Encryption Standard.
Claim 6
Dependent Claim
25 words
The method of performing encryption key management of claim 4 , wherein the Data Encryption Standard operates as a stream cipher in output feedback mode.
Claim 7
Dependent Claim
20 words
The method of performing encryption key management of claim 5 , wherein a keystream is applied only to payload bits.
Claim 8
Dependent Claim
23 words
The method of performing encryption key management of claim 3 , wherein a client device indicates supported encryption algorithms using beacon payload messages.
Claim 9
Dependent Claim
34 words
The method of performing encryption key management of claim 1 , wherein the encryption key update payload message includes a payload, and wherein the payload includes an initialization vector and a forward error correction.
Claim 10
Dependent Claim
26 words
The method of performing encryption key management of claim 8 , wherein the payload includes a logical network identifier currently in use in the logical network.
Claim 11
Dependent Claim
23 words
The method of performing encryption key management of claim 8 , wherein the forward error correction comprises a 32-bit cyclic redundancy code (CRC).
Claim 12
Dependent Claim
41 words
The method of performing encryption key management of claim 1 , wherein the creating step (b) comprises the sub-steps of: (1) computing a CRC over an entire encryption key update payload; and (2) encrypting a key field and a CRC field.
Claim 13
Dependent Claim
62 words
The method of performing encryption key management of claim 2 , wherein the creating a key update acknowledgment step (e) comprises the sub-steps of: (1) selecting a new initialization vector; (2) filling an encryption key field with the hard-wired key; (3) computing a CRC over an entire key update acknowledgment payload; and (4) encrypting the encryption key field and a CRC field.
Claim 14
Dependent Claim
68 words
The method of performing encryption key management of claim 2 , wherein the re-transmitting step (g) comprises the sub-steps of: (1) awaiting receipt of a beacon payload message from the at least one receiving device; and (2) re-transmitting the encryption key update payload message transmitted in sub-step (c) of claim 1 until the at least one originating client device receives the key update acknowledgment payload message, then terminating.
Claim 15
Dependent Claim
130 words
An encryption key management AC powerline networking circuit, comprising: (a) at least one originating client device, capable of receiving user input, adapted to input a hard-wired key and a password, wherein the originating client device is adapted to create an encryption key update payload message comprising a current network encryption key encrypted by the hard-wired key, and wherein the originating client device is adapted to transmit the encryption key update payload message to another client device; and (b) at least one receiving client device, operatively coupled to the at least one originating client device, wherein the receiving client device is adapted to receive the encryption key update payload message, and adapted to create a key update acknowledgment payload message comprising the hard-wired key encrypted by a current network encryption key.
Claim 16
Dependent Claim
130 words
An encryption key management AC powerline networking circuit, comprising: (a) at least one originating client device, capable of receiving user input, adapted to input a hard-wired key and a password, wherein the originating client device is adapted to create an encryption key update payload message comprising a current network encryption key encrypted by the hard-wired key, and wherein the originating client device is adapted to transmit the encryption key update payload message to another client device; and (b) at least one receiving client device, operatively coupled to the at least one originating client device, wherein the receiving client device is adapted to receive the encryption key update payload message, and adapted to create a key update acknowledgment payload message comprising the hard-wired key encrypted by a current network encryption key.
Claim 17
Dependent Claim
17 words
The circuit of claim 14 , wherein the receiving client device is incapable of receiving user input.
Claim 18
Dependent Claim
110 words
An AC powerline networking circuit for managing encryption keys, comprising: (a) means for inputting one of a hard-wired key and a password; (b) means, responsive to the input means, for encrypting a current network encryption key utilizing a hard-wired key and for encrypting the hard-wired key utilizing a current network encryption key; (c) means, operatively coupled to the encrypting means, for transmitting an encryption key update payload message to a first device and for transmitting a key update acknowledgment payload message to a second device; and (d) means, responsive to the transmitting means, for receiving a beacon, the encryption key update payload message and the key update acknowledgment payload message.
Claim 19
Dependent Claim
110 words
An AC powerline networking circuit for managing encryption keys, comprising: (a) means for inputting one of a hard-wired key and a password; (b) means, responsive to the input means, for encrypting a current network encryption key utilizing a hard-wired key and for encrypting the hard-wired key utilizing a current network encryption key; (c) means, operatively coupled to the encrypting means, for transmitting an encryption key update payload message to a first device and for transmitting a key update acknowledgment payload message to a second device; and (d) means, responsive to the transmitting means, for receiving a beacon, the encryption key update payload message and the key update acknowledgment payload message.
Claim 20
Dependent Claim
16 words
The circuit of claim 16 , wherein the first device is incapable of receiving user input.
Claim 21
Dependent Claim
185 words
An AC powerline networking circuit for managing encryption keys, comprising: (a) means for inputting one of a hard-wired key and a password to a first device; (b) a first encrypting means, responsive to the input means, for encrypting a current network encryption key utilizing a hard-wired key; (c) a first transmitting means, operatively coupled to the first encrypting means, for transmitting an encryption key update payload message to a second device; (d) a first receiving means, operatively coupled to the first transmitting means, for receiving the encryption key update payload message; (e) means, operatively coupled to the first receiving means, for decrypting the encryption key update payload message; (f) a second encrypting means, operatively coupled to the decrypting means, for encrypting the hard-wired key utilizing the current network encryption key; (g) a second transmitting means, operatively coupled to the second encrypting means, for transmitting a key update acknowledgment payload message to the first device; and (h) a second receiving means, operatively coupled to the second transmitting means, for determining if a beacon and the key update acknowledgment payload message is received by the first device.
Claim 22
Dependent Claim
185 words
An AC powerline networking circuit for managing encryption keys, comprising: (a) means for inputting one of a hard-wired key and a password to a first device; (b) a first encrypting means, responsive to the input means, for encrypting a current network encryption key utilizing a hard-wired key; (c) a first transmitting means, operatively coupled to the first encrypting means, for transmitting an encryption key update payload message to a second device; (d) a first receiving means, operatively coupled to the first transmitting means, for receiving the encryption key update payload message; (e) means, operatively coupled to the first receiving means, for decrypting the encryption key update payload message; (f) a second encrypting means, operatively coupled to the decrypting means, for encrypting the hard-wired key utilizing the current network encryption key; (g) a second transmitting means, operatively coupled to the second encrypting means, for transmitting a key update acknowledgment payload message to the first device; and (h) a second receiving means, operatively coupled to the second transmitting means, for determining if a beacon and the key update acknowledgment payload message is received by the first device.
Claim 23
Dependent Claim
16 words
The circuit of claim 18 , wherein the second device is incapable of receiving user input.
Claim 24
Independent Claim
161 words
A method of managing multiple MAC protocols in an AC powerline communication network system, wherein the communication network system comprises a plurality of devices, and wherein a first set of the plurality of devices uses a first MAC protocol and wherein a second set of the plurality of devices uses a second MAC protocol, and wherein the first MAC protocol is a previous MAC version and the second MAC protocol is a current MAC version, comprising the steps of: (a) selecting a newer-version MAC protocol device to control a blanking interval; (b) determining a period and a duration of the blanking interval of step (a); (c) transmitting a message at a predetermined interval, wherein the message specifies the period and the duration of the blanking interval; (d) allowing devices using the second MAC protocol to perform contention-based access during the blanking interval; and (e) allowing devices using the first MAC protocol to perform contention-based access during a special contention resolution slot.
Claim 25
Independent Claim
161 words
A method of managing multiple MAC protocols in an AC powerline communication network system, wherein the communication network system comprises a plurality of devices, and wherein a first set of the plurality of devices uses a first MAC protocol and wherein a second set of the plurality of devices uses a second MAC protocol, and wherein the first MAC protocol is a previous MAC version and the second MAC protocol is a current MAC version, comprising the steps of: (a) selecting a newer-version MAC protocol device to control a blanking interval; (b) determining a period and a duration of the blanking interval of step (a); (c) transmitting a message at a predetermined interval, wherein the message specifies the period and the duration of the blanking interval; (d) allowing devices using the second MAC protocol to perform contention-based access during the blanking interval; and (e) allowing devices using the first MAC protocol to perform contention-based access during a special contention resolution slot.
Claim 26
Dependent Claim
30 words
The method of managing multiple MAC protocols of claim 20 , wherein the current MAC version is a non-v1.0 MAC version and the previous version is a v1.0 MAC version.
Claim 27
Dependent Claim
19 words
The method of managing multiple MAC protocols of claim 20 , wherein the predetermined interval is approximately five seconds.
Claim 28
Dependent Claim
45 words
The method of managing multiple MAC protocols of claim 20 , wherein the determining step (b) comprises the sub-steps of: (1) monitoring communication traffic; and (2) determining a period and a duration for the blanking interval based upon the communication traffic monitored during sub-step (1).
Claim 29
Dependent Claim
33 words
The method of managing multiple MAC protocols of claim 20 , wherein the message is a medium blanking payload message, and wherein the medium blanking payload message specifies the period and the duration.
Claim 30
Dependent Claim
42 words
The method of managing multiple MAC protocols in an AC powerline communication network system of claim 20 , wherein the message comprises a medium blanking payload message and a beacon message, and wherein the beacon message specifies the period and the duration.
Claim 31
Dependent Claim
47 words
The method of managing multiple MAC protocols in an AC powerline communication network system of claim 20 , wherein the transmitting step (c) comprises transmitting a ROBO-mode broadcast packet including a medium blanking payload message, wherein the medium blanking payload message specifies the period and the duration.
Claim 32
Dependent Claim
40 words
The method of managing multiple MAC protocols in an AC powerline communication network system of claim 20 , wherein the message transmitted at the step (c) provides a network timing reference and network timing information pertaining to the blanking interval.
Claim 33
Dependent Claim
43 words
The method of managing multiple MAC protocols in an AC powerline communication network system of claim 20 , wherein the method further includes a random backoff step wherein devices having queued packets for transmission randomly transmit their queued packets after the blanking interval.
Claim 34
Dependent Claim
44 words
The method of managing multiple MAC protocols in an AC powerline communication network system of claim 20 , wherein the method further includes a random backoff step wherein devices having queued packets for transmission transmit their queued packets immediately subsequent to the blanking interval.
Claim 35
Independent Claim
119 words
A method of controller-less reservation based access in an AC powerline communication network system, wherein the communication network system includes a plurality of communication clients, comprising the steps of: (a) broadcasting a reservation establishment payload that establishes a reservation between an originating client and a recipient client; (b) determining a reservation schedule based upon clients that have active reservations, wherein the reservation schedule includes a plurality of reservation access periods, and wherein a specified originating client and a specified recipient client communicate during a specified reservation access period; (c) transmitting information between clients during the plurality of reservation access periods based upon the reservation schedule determined during step (b); and (d) determining whether to renew or to terminate reservations.
Claim 36
Independent Claim
119 words
A method of controller-less reservation based access in an AC powerline communication network system, wherein the communication network system includes a plurality of communication clients, comprising the steps of: (a) broadcasting a reservation establishment payload that establishes a reservation between an originating client and a recipient client; (b) determining a reservation schedule based upon clients that have active reservations, wherein the reservation schedule includes a plurality of reservation access periods, and wherein a specified originating client and a specified recipient client communicate during a specified reservation access period; (c) transmitting information between clients during the plurality of reservation access periods based upon the reservation schedule determined during step (b); and (d) determining whether to renew or to terminate reservations.
Claim 37
Dependent Claim
32 words
The method of controller-less reservation based access of claim 30 , wherein the step (a) of broadcasting a reservation establishment payload comprises broadcasting a ROBO mode packet comprising a reservation establishment payload.
Claim 38
Dependent Claim
30 words
The method of controller-less reservation based access of claim 30 , wherein the reservation establishment payload includes information pertaining to reservation start time, packet duration, transmission period and reservation lifetime.
Claim 39
Dependent Claim
31 words
The method of controller-less reservation based access of claim 30 , wherein the reservation includes a two-way reservation, and wherein the two-way reservation comprises a forward transmission and a reverse transmission.
Claim 40
Dependent Claim
45 words
The method of controller-less reservation based access of claim 30 , wherein the broadcasting ste p (a) comprises the sub-steps of: (1) broadcasting a ROBO mode packet including a reservation establishment payload; and (2) transmitt networking a reservation ackn owledgement payload from the recipient client.
Claim 41
Dependent Claim
24 words
The method of controller-less reservation based access of claim 33 , wherein the forward transmission and the reverse transmission have the same transmission period.
Claim 42
Dependent Claim
27 words
The method of controller-less reservation based access of claim 30 , wherein the reservation comprises a one-way reservation, and wherein the one-way reservation comprises a forward transmission.
Claim 43
Dependent Claim
27 words
The method of controller-less reservation based access of claim 30 , wherein reservations are renewed by broadcasting a ROBO mode packet including a reservation renewal payload message.
Claim 44
Dependent Claim
27 words
The method of controller-less reservation based access of claim 30 , wherein reservations are renewed and terminated only after the occurrence of a last reservation access period.
Claim 45
Dependent Claim
29 words
The method of controller-less reservation based access of claim 30 , wherein reservations are renewed and terminated only immediately subsequent to the occurrence of a last reservation access period.
Claim 46
Dependent Claim
45 words
The method of controller-less reservation based access of claim 30 , wherein reservations are terminated in accordance with the following sub-steps: (1) loading a zero value into a reservation lifetime field in a reservation renewal payload message; and (2) transmitting the reservation renewal payload message.
Claim 47
Independent Claim
88 words
A method of identifying logical networks in an AC powerline communication network system, wherein the communication network system comprises a plurality of communication clients, and wherein each client is uniquely associated with a logical network, the method comprising the steps of: (a) determining a unique logical network identifier (LNI) for a selected plurality of clients; (b) broadcasting information regarding the unique LNI; (c) creating tables that map client addresses to the LNI; and (d) communicating data only between the selected plurality of clients associated with the unique LNI.
Claim 48
Independent Claim
88 words
A method of identifying logical networks in an AC powerline communication network system, wherein the communication network system comprises a plurality of communication clients, and wherein each client is uniquely associated with a logical network, the method comprising the steps of: (a) determining a unique logical network identifier (LNI) for a selected plurality of clients; (b) broadcasting information regarding the unique LNI; (c) creating tables that map client addresses to the LNI; and (d) communicating data only between the selected plurality of clients associated with the unique LNI.
Claim 49
Dependent Claim
45 words
The method of identifying logical networks in an AC powerline communication network system of claim 41 , wherein the determining step (a) comprises the sub-steps of: (1) inputting a password; and (2) hashing the password to map the password to a logical network identifier (LNI).
Claim 50
Dependent Claim
39 words
The method of identifying logical networks in an AC powerline communication network system of claim 42 , wherein the hashing sub-step (2) comprises compressing the password into a 32-bit LNI by generating a 32-bit CRC code for the password.
Claim 51
Dependent Claim
33 words
The method of identifying logical networks in an AC powerline communication network system of claim 42 , wherein the password comprises a street address of an owner of the AC powerline communication network.
Claim 52
Dependent Claim
24 words
The method of identifying logical networks in an AC powerline communication network system of claim 42 , wherein the password comprises a network name.
Claim 53
Dependent Claim
30 words
The method of identifying logical networks in an AC powerline communication network system of claim 42 , wherein the password is input during installation of the AC powerline communication network.
Claim 54
Dependent Claim
33 words
The method of identifying logical networks in an AC powerline communication network system of claim 41 , wherein the LNI is communicated to the selected plurality of clients via a beacon payload message.
Claim 55
Dependent Claim
75 words
The method of identifying logical networks in an AC powerline communication network system of claim 43 , wherein the 32-bit CRC code for the password is formed by using an ASCII-mapped translation of the password in accordance with the following CRC polynomial: g ( x )= x 32 +x 26 +x 23 +x 22 +x 16 +x 12 +x 11 +x 10 +x 8 +x 7 +x 5 +x 4 +x 2 +x 1 +1.
Claim 56
Dependent Claim
42 words
The method of identifying logical networks in an AC powerline communication network system of claim 43 , wherein the LNI has a selected length of N bits, and wherein the LNI is obtained by generating an N-bit CRC code for the password.
Claim 57
Independent Claim
263 words
A method of controlling communication between devices in an AC powerline communication network system, wherein a first set of the devices uses a first MAC protocol and wherein a second set of the devices uses a second MAC protocol, wherein the first MAC protocol is a previous MAC version and the second MAC protocol is a current MAC version, and wherein medium blanking messages are transmitted on the network by a controlling one of the second set of devices, wherein the blanking messages contain blanking information that defines a blanking interval during which only the second set of devices are allowed to communicate, comprising the steps of: (a) determining whether a selected device is capable of receiving the blanking messages from the controlling device; (b) if the selected device is capable of receiving the blanking messages, assembling a respective and associated beacon message unique to the selected device, wherein the assembled beacon message is based upon information contained in received blanking messages, and wherein the beacon message includes blanking information contained in the received blanking messages, and proceeding to step (d), else proceeding to step (c); (c) if the selected device is incapable of receiving the blanking messages, assembling the beacon message based upon beacon messages received from other network devices, wherein each beacon message includes a lifetime field that is used by all of the devices in determining whether to use a received beacon message when assembling their respective and associated beacon messages; and (d) periodically transmitting the beacon message assembled in steps (b) or (c) to other devices in the network.
Claim 58
Independent Claim
263 words
A method of controlling communication between devices in an AC powerline communication network system, wherein a first set of the devices uses a first MAC protocol and wherein a second set of the devices uses a second MAC protocol, wherein the first MAC protocol is a previous MAC version and the second MAC protocol is a current MAC version, and wherein medium blanking messages are transmitted on the network by a controlling one of the second set of devices, wherein the blanking messages contain blanking information that defines a blanking interval during which only the second set of devices are allowed to communicate, comprising the steps of: (a) determining whether a selected device is capable of receiving the blanking messages from the controlling device; (b) if the selected device is capable of receiving the blanking messages, assembling a respective and associated beacon message unique to the selected device, wherein the assembled beacon message is based upon information contained in received blanking messages, and wherein the beacon message includes blanking information contained in the received blanking messages, and proceeding to step (d), else proceeding to step (c); (c) if the selected device is incapable of receiving the blanking messages, assembling the beacon message based upon beacon messages received from other network devices, wherein each beacon message includes a lifetime field that is used by all of the devices in determining whether to use a received beacon message when assembling their respective and associated beacon messages; and (d) periodically transmitting the beacon message assembled in steps (b) or (c) to other devices in the network.
Claim 59
Dependent Claim
38 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein the current MAC version is a non-v1.0 MAC version and the previous MAC version is a v1.0 MAC version.
Claim 60
Dependent Claim
43 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein the lifetime field of the assembled beacon message is set to zero whenever the selected device receives a blanking message from the controlling device.
Claim 61
Dependent Claim
47 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein the lifetime field of the assembled beacon message is set to a non-zero number whenever the selected device is incapable of receiving blanking messages from the controlling device.
Claim 62
Dependent Claim
44 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein the selected device is determined incapable of receiving blanking messages only if it has not received a blanking message within a predetermined threshold of time.
Claim 63
Dependent Claim
25 words
The method of controlling communication between devices in an AC powerline communication network system of claim 54 , wherein the predetermined threshold comprises 5 seconds.
Claim 64
Dependent Claim
43 words
The method of controlling communication between devices in an AC powerline communication network system of claim 53 , wherein the non-zero number comprises a lowest lifetime field value of all beacon messages received by the selected device within a predetermined recent time period.
Claim 65
Dependent Claim
29 words
The method of controlling communication between devices in an AC powerline communication network system of claim 56 , wherein the recent time period comprises the most recent 5 seconds.
Claim 66
Dependent Claim
67 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein when the selected device is incapable of receiving blanking messages, the selected device assembles its respective and associated beacon message based upon a received basis beacon message, wherein the basis beacon message comprises a received beacon message having a lowest lifetime field value of all received beacon messages.
Claim 67
Dependent Claim
36 words
The method of controlling communication between devices in an AC powerline communication network system of claim 58 , wherein only beacon messages received within a recent time period are considered in determining the basis beacon message.
Claim 68
Dependent Claim
29 words
The method of controlling communication between devices in an AC powerline communication network system of claim 59 , wherein the recent time period comprises the most recent 5 seconds.
Claim 69
Dependent Claim
50 words
The method of controlling communication between devices in an AC powerline communication network system of claim 59 , wherein when two or more received beacon messages have equally low lifetime field values, the basis beacon message comprises a most recently received beacon message having the equally low lifetime field value.
Claim 70
Dependent Claim
46 words
The method of controlling communication between devices in an AC powerline communication network system of claim 59 , wherein the selected device sets a lifetime field value of its assembled beacon message equal to the lifetime field value of the basis beacon message, incremented by one.
Claim 71
Dependent Claim
31 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein the lifetime field value of all beacon messages has a predetermined maximum.
Claim 72
Dependent Claim
24 words
The method of controlling communication between devices in an AC powerline communication network system of claim 63 , wherein the predetermined maximum is 7.
Claim 73
Dependent Claim
55 words
The method of controlling communication between devices in an AC powerline communication network system of claim 63 , wherein when all of the beacon messages transmitted on the network have lifetime field values equal to the maximum, the blanking interval is assumed to be nonexistent, and the devices are allowed to transmit at any time.
Claim 74
Dependent Claim
45 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein the beacon messages are used to specify a period and duration of the blanking interval, and an exact time instant at which the blanking interval begins.
Claim 75
Dependent Claim
34 words
The method of controlling communication between devices in an AC powerline communication network system of claim 50 , wherein the beacons contain information regarding the capability and limitation of the devices in the network.
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USPTO Annuity & Maintenance Windows
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| 7.5 Years (Year 8) | 2012-02-08 | 2012-08-09 | 2013-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2016-02-08 | 2016-08-09 | 2017-02-08 | $7700.00 | Window Closed / Lapsed |