Base station

About: Base station is a research topic. Over the lifetime, 85883 publications have been published within this topic receiving 1019303 citations. The topic is also known as: Mobile phone base stations & BS.

Wireless direct sequence spread spectrum digital cellular telephone system

Abstract: The base station (10) serves up to 62 handsets (11-1, 11-2, ..., 11-N) and has a single antenna (13); however, polarization diversity is provided in each of the handsets (11-1, 11-2, ..., 11-N) by using dual cross polarized antennae (11A1 and 11A2). The base station (10) includes an up/down converter and distribution amplifiers (14); a transceiver (12) for each handset (11-1, 11-2, ..., 11-N); a common reference oscillator (15); a telephone system interface (17); and clock logic circuitry (16).

Wireless digital personal communications system having voice/data/image two-way calling and intercell hand-off

Abstract: A wireless digital personal communications system (or PCS) having a plurality of radio cell base stations, fixed terminals, and portable handset terminals, each having a predetermined radio cell coverage area. The wireless PCS has a full digital network interface. The personal communications system facilitates the interconnection and switching of PCS call traffic through the digital network interface and the public switched telephone network, or any switched network. The personal communications system has voice/data/image (or any combination thereof) and incoming and outgoing calling capability. The PCS is fully operational and compatible with any and all modulation approaches selected for wireless communications. The intercell protocol hand-off being provided through distributed logic which is implemented in software that is resident in the intelligent portable handset terminals, in the intelligent fixed terminals, in the intelligent base stations, and in the public switched telephone network (or any switched network). Alternative embodiments of the present invention include a wireless digital personal communications system having authentication means for authenticating a remote device; a wireless digital personal communications system having a combination of authentication means for authenticating a remote device and security means for securing signal and message content between an intelligent base station and a remote device, the security means including a predetermined encryption and decryption technique; a wireless digital personal communications system having dynamic zone grouping of portable handset terminals or fixed terminals; and a wireless digital personal communications system having call forwarding for unanswered calls.

Workgroup report: base stations and wireless networks-radiofrequency (RF) exposures and health consequences.

Abstract: Radiofrequency (RF) waves have long been used for different types of information exchange via the airwaves—wireless Morse code, radio, television, and wireless telephony (i.e., construction and operation of telephones or telephonic systems). Increasingly larger numbers of people rely on mobile telephone technology, and health concerns about the associated RF exposure have been raised, particularly because the mobile phone handset operates in close proximity to the human body, and also because large numbers of base station antennas are required to provide widespread availability of service to large populations. The World Health Organization convened an expert workshop to discuss the current state of cellular-telephone health issues, and this article brings together several of the key points that were addressed. The possibility of RF health effects has been investigated in epidemiology studies of cellular telephone users and workers in RF occupations, in experiments with animals exposed to cell-phone RF, and via biophysical consideration of cell-phone RF electric-field intensity and the effect of RF modulation schemes. As summarized here, these separate avenues of scientific investigation provide little support for adverse health effects arising from RF exposure at levels below current international standards. Moreover, radio and television broadcast waves have exposed populations to RF for > 50 years with little evidence of deleterious health consequences. Despite unavoidable uncertainty, current scientific data are consistent with the conclusion that public exposures to permissible RF levels from mobile telephony and base stations are not likely to adversely affect human health.

Energy-Efficient Wake-Up Scheduling for Data Collection and Aggregation

Abstract: A sensor in wireless sensor networks (WSNs) periodically produces data as it monitors its vicinity. The basic operation in such a network is the systematic gathering (with or without in-network aggregation) and transmitting of sensed data to a base station for further processing. A key challenging question in WSNs is to schedule nodes' activities to reduce energy consumption. In this paper, we focus on designing energy-efficient protocols for low-data-rate WSNs, where sensors consume different energy in different radio states (transmitting, receiving, listening, sleeping, and being idle) and also consume energy for state transition. We use TDMA as the MAC layer protocol and schedule the sensor nodes with consecutive time slots at different radio states while reducing the number of state transitions. We prove that the energy consumption by our scheduling for homogeneous network is at most twice of the optimum and the timespan of our scheduling is at most a constant times of the optimum. The energy consumption by our scheduling for heterogeneous network is at most ? (log Rmax/Rmin) times of the optimum. We also propose effective algorithms to construct data gathering tree such that the energy consumption and the network throughput is within a constant factor of the optimum. Extensive simulation studies show that our algorithms do considerably reduce energy consumption.

Method and apparatus for providing reserve power in a cellular telephone

Abstract: Reserve power is provided in a portable cellular transceiver comprising a Global Positioning System (GPS) receiver by monitoring a power level of a battery of the portable cellular transceiver using a power detection circuit. A comparator circuit determines whether the power level of the battery is greater than a predetermined threshold. Based on the available power level, a power control circuit automatically places the transceiver into at least one low power mode when the power level reaches a corresponding threshold level. The low power mode selectively powers down circuitry of the portable cellular transceiver. The corresponding threshold level reserves power for an emergency telephone call. Power is provided to the circuitry of the portable cellular transceiver when the available power level is greater than the predetermined threshold. The reserve power provides power for the activation of the portable cellular transceiver, establishment of a call between the portable cellular transceiver and a cellular base station, transfer of GPS satellite acquisition aiding information to the portable cellular transceiver, receipt of GPS satellite information, communication of GPS satellite information to the cellular base station, and determination of a position of the portable cellular transceiver. The emergency telephone call may be a single button enhanced 911 call.