摘要:
A method for creating a secure sub-network on a public network that includes a set of devices. The secure sub-network is to include a subset of devices from among the set of devices. An access card is provided having a first private key comprised thereon. The access card is scanned to determine the first private key, by the subset of devices. A master device is determined from among the subset of devices. A second private key is selected and a public key is computed based on the second private key, by the master device. The second private key is only known to the master device. The public key is sent to the set of devices, by the master device. A shared encryption key is computed, and an encryption is requested of any subsequent messages between any of the devices comprising the subset of devices using the shared encryption key.
摘要:
A method for hierarchically block coding a packet stream includes the steps of appending a packet error correction code to each packet in the packet stream and appending a block error correction code to successive blocks of packets in the packet stream to form a hierarchically error correction coded packet stream. This packet stream is then transmitted through a communications channel. Errors are corrected in each block of packets in response to each block error correction code and errors are corrected in each packet in each block in response to each packet error correction code.
摘要:
There is provided a method of diversity error control coding for a system having variable-length packets that carry prioritized data. High priority packets in a data sequence are replicated to form virtual replications. Parity symbols are generated from the data sequence and from the virtual replications, and tag information is generated that indicates a number of the virtual replications used to generate the parity symbols, for subsequent transmission of only the data sequence, the parity symbols, and the tag information to reconstruct the data sequence.
摘要:
An apparatus and method of clock synchronization of a powerline modem network for a plurality of devices are provided. A plurality of devices are provided having a powerline modem and a clock (100). The powerline modem permits communication between the plurality of devices over a powerline network. A synchronization message is provided over the powerline network (102). The synchronization message includes an instruction for each of the plurality of devices to update their clock in accordance with a clock time provided in the synchronization message (104). A synchronization device may be provided to update device clocks on a powerline network.
摘要:
Synchronization of a powerline modem network (10) with a plurality of devices is provided. A plurality of devices (16 and 18) each include a powerline modem (20) and a clock circuit (22) for synchronizing a data rate. The powerline modem permits data transmission between the plurality of devices over a powerline network on data carriers (28). A synchronization signal is transmitted over the powerline network. The synchronization signal includes a carrier (30) operating at a frequency different from the data carriers. The synchronization signal provides each of the plurality of devices a time reference to synchronize the data rate.
摘要:
A method and apparatus for detecting the presence of a wireless local area network (WLAN) (104) detects at least one signature sequence in a radio frequency (RF) signal associated with a WLAN (104). The present invention indicates the presence of a WLAN (104) in response to the detection of the at least one signature sequence in the RF signal.
摘要:
A method for creating a secure powerline modem network transmits a private key (y) individually to each of the plurality of powerline modem devices (22) to be secured in a network such that each powerline modem device receives the private key in isolation of the network. Each of the plurality of powerline modem devices store the private key. A public key (X) is computed by a master device (32) in the network to be secured. The public key is transmitted from the master device to the plurality of devices. A shared key (Y) is computed at each of the plurality of powerline devices based on the public key and the private key, and communication within the secured network is performed by employing messages encrypted based on the shared key.
摘要:
In a network system having a plurality of devices communicating via a network, a method and system for providing an emergency signal is provided. In one embodiment, a device is malfunctioning if the device continuously transmits data to the network without proper authorization. Another properly functioning device transmits the emergency signal via an auxiliary channel to the malfunctioning device. The auxiliary channel is a separate channel supporting the transmission of the emergency signal. The malfunctioning device receives the emergency signal and disables itself in response to this signal.
摘要:
A portable security device (10) for setting up secure powerline modem networks is disclosed. The portable security device includes a memory (18) which stores a protocol (19) for communicating with powerline modem devices (e.g., 22), and a socket (14) configured to receive a power cord (23) from a powerline modem device (22). A number assigning device (12 or 16) transmits a private key to powerline modem devices such that the private key is stored in the powerline modem devices and is used to associate a plurality of powerline modem devices and exclude unauthorized powerline modem devices.
摘要:
An Orthogonal Frequency Division Multiplexing (OFDM) receiver that employs N second-order phase-lock loops sharing a common integrator (where N is the number of pilots in the system). The N second order phase-lock loops track out independent pilot phase rotations to facilitate the constructive averaging of the pilots' phase information. At the same time, by sharing a common integrator, the OFDM receiver takes advantage of noise averaging over multiple pilots to obtain a cleaner frequency offset estimation. The OFDM receiver may also compensate for FFT window drift by calculating a phase difference between a selected pair of pilots and tracking the rate of change of the calculated phase difference over time. The calculated phase difference is used to control the position of an upstream FFT window after a predetermined phase difference threshold is exceeded. The tracked rate of change is used to continuously adjust the phase of downstream equalizer taps.