The invention concerns medical diagnosis and monitoring equipment with wireless electrodes (2a...2f) designed to be secured to the skin of the patient (3). The electrodes (2a...2f) include, as well as microsensors, a digital transmitter (31) and receiver (30) unit and an antenna (36a). The electrodes (2a...2f) can be used, for instance, to detect EEG and ECG signals or to monitor body/berathing movements, temperature or perspiration. A preferred embodiment has an electrode which incorporates all functions in a semiconductor chip designed as an integrated circuit with the appropriate sensor, sensor-control, frequency-generation, transmitter and receiver units plus a switching control unit. The antenna (36a) can be mounted either in the flexible electrode covering or directly on the chip.

Wireless medical diagnosis and monitoring equipment

This article presents an overview of the current state of wireless communications, including relevant ongoing activities in technology development, standards, and spectrum allocation. The authors discuss cellular radio, cordless telephony, and wireless data systems. Ongoing and planned future developments are summarized. The presentation is oriented toward broad coverage rather than technical depth. However, brief discussions of the air interfaces for existing digital cellular and digital cordless systems are provided, because the air interface bears heavily on system capacity and the environments in which the system can be used, as well as on the cost and complexity of the equipment. >

Overview of wireless personal communications

For bidirectional transmission of packet data, a packet data service unit (Agent) is disposed in a digital cellular system connected to be in association with a Mobile Switching Center, and connecting the cellular network to the date network. As a mobile station is connected to the packet data service unit, signalling related to connection formation characteristics of the network is first accomplished. As a result thereof, the mobile station and the data service unit are provided with a number of stored parameters relating to each other. This situation creates or is called a virtual channel. When a mobile station wants to transmit or receive data packets between the mobile station and the data service unit a packet data transfer channel is established making use of the parameters of the virtual channel and thereby using substantially less signalling than the channel establishment signalling characteristic of the network, one part thereof being a radio channel and the other part a time slot in a digital trunk line. On termination of data packet transfer, at least said radio channel is disassembled but the virtual channel is maintained until the disconnection of the mobile station from the data service.

Data transmission in a radio telephone network

A method and apparatus of communicating information using Time Division Multiple Access and adaptive transmission and reception are disclosed. Signal bursts are transmitted from TDMA transmitters to a TDMA receiver wherein the transmitter codes the information and transmits coded information to the receiver using at least one of two timeslots of a plurality of timeslots in a repetitive TDMA frame period. Both of the two timeslots are received whether or not the transmitter has transmitted using one or two timeslots and the received signals are classified as intended and non-intended. Successively received signals classified as intended are then assembled into a block for decoding to reproduce the information.

Dual mode satellite/cellular terminal

The invention relates to a method for transmitting packet data in a cellular system. The number of time slots in a TDMA frame dedicated for packet transmission varies according to transmission needs and each logical channel consisting of corresponding time slots in consecutive TDMA frames is independent of the other logical channels. A data packet is encoded in an information channel frame consisting of N-1 information bursts, and between the frames there can be an acknowledge/retransmission request burst (ARQ) reporting that a received frame was error-free or requesting retransmission. Thus, the information channel consists of repeated sequences of N bursts. Also disclosed are the structure of a packet paging burst (PP), packet random access burst (PRA), packet access grant burst (PAG), acknowledge/retransmission request burst (ARQ) as well as the use of the bursts in starting and maintaining the transmission.

A system for transmitting packet data in radio telephone TDMA systems

The groupe speciale mobile (GSM) digital cellular radio system, to be introduced into Europe in 1991, is the first standardised cellular radio system to use digital transmission. Given the novel design of the system considerable effort has gone into producing the system specifications. These have been centred on the two major interfaces present in the system ― the mobile switch to base station interface and the base to mobile station (radio) interface. The paper describes the GSM radio interface in detail, covering both the traffic and signalling channels

M. R. L. Hodges

Papers

The GSM radio interface