Abstract: The writing address supply part 210 supplies writing addresses for writing the bits forming bit sequences corresponding to the header H contained in a frame to be transmitted or stored and bit sequences corresponding to the data D, into the operating memory 220. The reading address supply part 230 alternately supplies to the operating memory 220 a plurality of addresses for reading a plurality of continuous bits corresponding to the header H from the operating memory 220, and an address for reading 1 bit corresponding to the data D from the operating memory 220, and reads the bit sequence such that the bits forming the bit sequence corresponding to the header H are scattered and arranged within the bit sequence forming the data D, from the operating memory. In accordance with such an interleaving device, it is possible to individually randomize frames according to their constituent data, and it is possible to transmit the bits that make up such data in a format which is most suited for said data.

Abstract: Cryptographically Protected Prefixes (“CPPs”) are used to create IP addresses, preventing any correlation between a CPP IP address and a host's geographic location. An IP address is subdivided into address prefixes of multiple segments. Each segment is encrypted with a cryptographic key known only to a subset of routers in the access network domain (or Privacy Domain). Therefore, each router obtains the information it needs to forward a packet of information, but not any additional information.

Abstract: The writing address supply part 210 supplies writing addresses for writing the bits forming bit sequences corresponding to the header H contained in a frame to be transmitted or stored and bit sequences corresponding to the data D, into the operating memory 220. The reading address supply part 230 alternately supplies to the operating memory 220 a plurality of addresses for reading a plurality of continuous bits corresponding to the header H from the operating memory 220, and an address for reading 1 bit corresponding to the data D from the operating memory 220, and reads the bit sequence such that the bits forming the bit sequence corresponding to the header H are scattered and arranged within the bit sequence forming the data D, from the operating memory. In accordance with such an interleaving device, it is possible to individually randomize frames according to their constituent data, and it is possible to transmit the bits that make up such data in a format which is most suited for said data.

Abstract: A method for location estimation employs filtering in both the radio signal domain and the space domain separately. The method filters raw values of the run-time radio signal measurements to reject distorted inputs. A region of confidence (RoC) is formed according to certain algorithms. Only location estimates falling within the RoC are considered for further processing. The location estimate candidates filtered by the RoC are put in a number of time-indexed bins. Each of the bins contains location estimate candidates obtained at similar times. A shortest route connecting a candidate from each bin is calculated to further improve the accuracy of the location estimation.

Abstract: The present invention provides a method and system for handoff in a wireless communication network. In one embodiment, a common handoff encryption key is generated by an authentication server and transmitted to a first access point and a second access point. The first access point transmits the handoff encryption key to a wireless terminal. The wireless terminal encrypts output data with the handoff encryption key. When the wireless terminal is associated with the second access point, the second access point decrypts data from the wireless terminal with the handoff encryption key. In a second embodiment, a handoff WEP key generation secret parameter is provided to a first and a second access point. Both access points generate a handoff WEP key as a function of the handoff WEP key generation secret parameter and an address of a wireless terminal. The first access point transmits the handoff WEP key to the wireless terminal.

Abstract: In an RF environment serviced by 802.11, Bluetooth (TM), or other network transmitters, or combinations, location-estimation methods and systems can advantageously use redundancy to refine an estimated location of an RF receiver. In one embodiment, a method for finding a receiver's location includes receiving signals from fixed transmitters, calculating preliminary location estimates, and combining the estimates using predetermined reference information on the RF environment. The reference information preferably includes minimum mean-squared error optimizing coefficients.

Abstract: A network system includes a network edge point configured to provide a terminal with access to a network. The network edge point includes a security policy associated with the terminal, and controls communications between the network and the terminal according to the security policy. The security policy may include a personal filter downloaded from the terminal, a service filter downloaded from a service policy server, and/or a domain filter downloaded from a domain policy server. The terminal may access the network through a second network edge point. The second network edge point may download one or more of the filters from the first network edge point, and control communications between the network and the terminal according to the security policy.

Abstract: A variable length frame transmission method making it possible to accurately and easily establish synchronism at the receiver side without redundancy of system under an environment in which a code error easily occurs. In a transmitter, a variable length frame division section 1 divides a variable length frame f into code strings f1 and f2 having a length ratio of 1:1. A first synchronization flag addition section 3-1 adds a synchronization flag S1 to the head of the code string f1 and a second synchronization flag addition section 3-2 adds a synchronization flag S2 to the head of the code string f2. The synchronization flags have contents different from each other, but they have the same length. Code strings having synchronization flags are multiplexed by a changeover switch 4 and formed into a variable length frame. A series of variable length frames obtained from the changeover switch 4 are transmitted to a receiver as serial data.

Abstract: In a network, a router uses some secret information combined with a cryptographic process in determination of a subnet's routing prefix.

Abstract: The probability of frame destruction is lowered while suppressing the redundancy of the transmission data. On the transmitting side, a predetermined unique word is contained in a frame n for storing the n-th data, and header information n, frame length information and header information n−1 of the frame n−1 one frame before the frame n are subjected to error-correcting coding, contained in the frame n, and transmitted. On the receiving side, the header of the frame n is received. When the frame length information is transmitted with error, the timing is specified by detecting the unique word and header information in the next frame n+1. When the header of the frame n is not successfully decoded, the information data of the frame n is decoded by using the header information n inserted into a predetermined position of the frame n+1.

Abstract: A congestion state of a transmission path between a transmitting terminal device and a receiving terminal device is analyzed, a transmission state of media packets between the transmitting terminal device and the receiving terminal device is analyzed, and qualities of the media packets to be transmitted by the transmitting terminal device is controlled according to the transmission path congestion state analysis result and the transmission state analysis result.

Abstract: A packet transmission method for transmitting packets classified according to a quality of service (QoS) requirement from a transmitting node to a receiving node is provided. In the transmitting node, the steps of: selecting sequentially a QoS class; dividing a queued packet to be transmitted belonging to the selected class into a plurality of predetermined data units, and transmitting one of the obtained predetermined data units; and applying a transmitter-side retransmission control process to the data unit to be transmitted when the selected class is a QoS class specified for data type packets are provided.

Abstract: An encryption apparatus and an encryption method are provided which can prevent a cryptographic key or authentication key from being broken. A voice stream is transmitted from a transmitting terminal to a receiving terminal. A bit stream of the voice stream includes speech bursts and speech pauses. Although the speech bursts are encrypted or provided with authentication information, the speech pauses are not encrypted or provided with authentication information, and are transmitted without change. Thus carrying out the encryption or the assignment of the authentication information selectively in accordance with the type of the bit stream makes it possible to prevent the cryptographic key or authentication key from being broken. Besides, it can reduce the processing amount of the encryption or authentication process, thereby being able to limit an increase in the information amount.

Abstract: The frame-forming data computing part 101 sorts a plurality of types of parameters forming the frames, and generates frame-forming data that contains data relating to the configuration of said frames and data establishing for each class the error protection method to be applied to each said parameter. The frame-forming data error protection processing part 102 implements the specified error protection for said frame-forming data. The class data error protection processing part 103 implements error protection that is specified for each class according to the frame-forming data, with respect to the parameters that are sorted into a plurality of classes. The synthesizer 104 transmits the frame-forming data that has undergone the specified error protection and the parameters that have undergone the error protection established for each class.

Abstract: A content distribution system is provided in which the content distribution system includes at least a content distribution server, a computer system and a content receiving terminal, the computer system including: a part for generating a content selection document including content location information; and a part for sending the content selection document to the content receiving terminal; the content receiving terminal including: a part for receiving the content selection document from the computer system; an part for extracting the content location information from the content selection document; a part for sending a distribution request for the content to the content distribution server; and a part for receiving the content from the content distribution server.

Abstract: A sender converts a non-compressed packet, which is to be transmitted, into a full-header packet including a full header or a header-compressed packet including a compressed header, and sends the converted packet to a receiver. The receiver receives the packet transmitted from the sender, and converts the received packet into a decompressed packet. In cases the full-header packet or header-compressed packet is lost between the sender and receiver, the receiver keeps header-compressed packers received during an interval from the packet loss to the next earliest reception of a full-header packet, and decompresses the compressed headers of the kept header-compressed packets on the basis of contents of the full header of the full-header packet.

Abstract: A mobile terminal is provided with an imaging unit for acquiring a plurality of frames of images including a search object and a feature descriptor generating unit for generating a feature descriptor from an image of a search object included in the frames. The mobile terminal transmits the feature descriptor generated by the feature descriptor generating unit to a search server. The search server has a matching processing unit. The matching processing unit searches for a record matching with the feature descriptor received from the mobile terminal from a database of the content server.

Abstract: A delay unit 103 adds holding time that has been set by a holding time setting unit 104 to a received data. The holding time is computed based on delay time of received data and the minimum delay time of data received up to a certain point for the purpose of reducing a total delay time. The delay time is estimated in a delay time estimating unit 106 from the difference between a reception time of a packet counted based on an internal clock generator 107 and a time designated by a time stamp in the received packet.

Abstract: Under the situation in a network including a transmitter and a receiver in which a transmitter converts a non-compressed packet to be transmitted into a full-header packet including a full header or a header-compressed packet including a compressed header, and sends the converted packet to the receiver, the transmitter sends at least important packet in the non-compressed packet to be transmitted as a full-header packet. The important packet means for example, a packet containing the data serving an important role when the data terminal eventually receiving each packet reproduces the audio and/or image in accordance with the data in each of the packet.

Abstract: A sender converts a non-compressed packet, which is to be transmitted, into a full-header packet including a full header or a header-compressed packet including a compressed header, and sends the converted packet to a receiver. The receiver receives the packet transmitted from the sender, and converts the received packet into a decompressed packet. In cases the full-header packet or header-compressed packet is lost between the sender and receiver, the receiver keeps header-compressed packers received during an interval from the packet loss to the next earliest reception of a full-header packet, and decompresses the compressed headers of the kept header-compressed packets on the basis of contents of the full header of the full-header packet.