摘要:
In a wireless telecommunications network, transporting identification information, such as access point identifier (AP ID) and wireless terminal identifier (WT ID) information, in each uplink and each downlink protocol data unit (PDU) being transmitted between a sender and a receiver, without increasing bandwidth requirements. This is accomplished by modifying each PDU as a function of a first identification vector, prior to transmission, wherein the first identification vector reflects, for example, the AP ID and the corresponding WT ID. At the receiver, the PDU is re-modified as a function of a second identification vector, wherein the second identification vector reflects an expected AP ID and WT ID. If the receiver is the intended recipient of the PDU, the first and second identification vectors will be the same, and the process of re-modifying the PDU merely serves to restore the original value of the PDU. The receiver can detect whether the original value of the PDU has been restored through a data integrity check, for example, one which employs a cyclic redundancy code (CRC). The result can then be used to determine whether the receiver is, in fact, the intended receiver, and whether the receiver should decode the PDU or discard it.
摘要:
The present invention relates to a mobile communication system which comprises a base station (BTS1) having a data transmission connection to a mobile services switching centre (MSC) through a transcoder unit (TRCU). In order to improve the data transmission connection between the base station and the transcoder unit, the data transmission connection in question is partly composed of a packet-switched data transmission connection (4) to which a converter means (3) is arranged comprising means for converting the TRAU frame received into a packet to be transmitted over the packet-switched connection (4), the conversion including the removal of bits included in the TRAU frame and not needed on the packet-switched connection (4).
摘要:
A speech transmitting device includes a signal processing unit for carrying out plural types of speech signal processes by using a speech signal in a received packet, an alignment state detecting unit for detecting an alignment state of the received packet, and a process selecting unit for selecting a speech signal process which corresponds to the alignment state being detected by the alignment state detecting means, based on a selection reference used to select the speech signal process in correspondence to the alignment state of the received packet, and then outputting a result which is processed by the signal processing means according to the selected speech signal process.
摘要:
In a single-carrier or multi-carrier modulator (MOD), data symbols are modulated on at least one carrier in accordance with at least one constellation scheme. Idle data symbols are replaced by null data symbols and the latter null data symbols are associated with a low power constellation point of the at least one constellation scheme. The constellation points associated with the data symbols are randomly transformed into constellation points of equal power. In this way, idle data symbols are transferred with minimised power and sufficiently randomised to allow equaliser training and/or tracking at the receiving demodulator (DMOD) and to avoid high crest factors in multi-carrier systems.
摘要:
L'invention concerne un procédé de codage d'un bloc de données comprenant une première et une deuxième zones, le procédé étant de type consistant à appliquer un codage produit à ce bloc. Il comprend un premier codage bloc appliqué à la première zone, un deuxième codage bloc appliqué à la deuxième zone et un troisième codage bloc appliqué aux données obtenues par les deux premiers codage, dans un sens perpendiculaire aux deux premiers codes, les trois codages étant réalisés à l'aide de codes BCH, la première zone étant protégée par un code plus puissant que la deuxième zone. Le bloc est constitué par une cellule ATM, la première zone correspondant à l'entête de la cellule ATM et la deuxième zone au champ de données utiles de cette cellule ATM.
摘要:
A communications system is provided which supports asynchronous transfer mode (ATM) communications. An ATM multiplexer is located at a customer's premises and connected to customer premises voice and data equipment. A central office ATM multiplexer is connected to various different networks in the existing network infrastructure. The central office ATM multiplexer is preferably connected to networks such as a low-speed packet-switched network, a public circuit-switched network, a private line network, and a high-speed packet-switched network. The ATM multiplexer located at the customer premises preferably supports dynamic bandwidth allocation. Additional features provided by the communications system include the ability to provide different voice encoding schemes for different users based on calling party or called party information.
摘要:
The invention provides a device (1) for encrypting or decrypting data packets, comprising storage means (14) for temporarily storing data packets, identification means (15) for identifying data packets, processing means (11, 12, 13) for cryptographically processing data packets, and memory means (16) for storing cryptographic information. The processing means (11, 12, 13) comprise, according to the invention, a first (11) and a second (12) cryptographic element, the first cryptographic element (11) being designed for generating, on the basis of a first starting value, processing data for cryptographically processing a data packet, and the second cryptographic element (12) being designed for generating, on the basis of a second starting value, the first starting value. In addition, the processing means (11, 12, 13) according to the invention are designed for forming, on the basis of a cryptographically processed data packet, the second starting value, thereby ensuring the synchronization between corresponding encrypting and decrypting devices.