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 communication terminal having video image capability

Abstract: A wireless communication terminal is configured for enabling a user to receive and transmit video images as well as receive and transmit audio or speech signals associated with the user of the terminal and another user at, for example, a remote location. The received video image is obtained from a video image signal received over a radio frequency communications link established between the wireless communication terminal and a cellular base station. This received video image is displayed in a video image display conveniently associated with the wireless communication terminal. The transmitted video image signal may be that of the user of the terminal, of a scene within the field of view of the video camera or of text either coupled to the terminal through one of many well known data interfaces, or an image of text as captured by the camera. This transmitted video image signal is obtained from a video camera associated with the wireless communication terminal and then transmitted over the radio frequency communications link established between the wireless communication terminal and the cellular base station for displaying in a remotely located video image display.

Power control for a spread spectrum cellular mobile radio system

Abstract: In two earlier papers (ICC'80 [3] and GLOBECOM'82 [6]) two power control schemes for spread spectrum cellular land mobile radio have been described, one for the upstream (mobile to base) link and one for the downstream link Here we compare the power control problem for the upstream and the downstream links and show that using simple algebra we can equalize the signal-to-interference ratio for each mobile in a given cell in both links and thereby increase the capacity by 30 to 100% compared with a system with no power control We also show that the SIR values can be equalized system-wide for both link directions by means of a nontrivial eigenvalue problem, which results in a further capacity improvement of 10 to 15% Denial statistics are also presented

Performance of cellular networks with relays and centralized scheduling

Abstract: Future cellular wireless networks could include multihop transmission through relays. We propose a centralized downlink scheduling scheme in a cellular network with a small number of relays. The scheduling scheme has the property that it guarantees stability of the user queues for the largest set of arrival rates. We obtain throughput results by simulation for various scenarios and study the effect of number of relays, relay transmit power relative to the base station (BS) power, and the effect of distributing a given total power between the BS and different numbers of relays. We also present results for the case without channel fading to determine what fraction of the throughput gain is achieved from diversity reception. We find that, with four relays deployed in each sector, it is possible to achieve significant throughput gain including the signaling overhead.

Services and applications for a communications network

Abstract: A location system is disclosed for commercial wireless telecommunication infrastructures The system is an end-to-end solution having one or more location centers for outputting requested locations of commercially available handsets or mobile stations (MS) based on, eg, CDMA, AMPS, NAMPS or TDMA communication standards, for processing both local MS location requests and more global MS location requests via, eg, Internet communication between a distributed network of location centers The system uses a plurality of MS locating technologies including those based on: (1) two-way TOA and TDOA; (2) pattern recognition; (3) distributed antenna provisioning; (5) GPS signals, (6) angle of arrival, (7) super resolution enhancements, and (8) supplemental information from various types of very low cost non-infrastructure base stations for communicating via a typical commercial wireless base station infrastructure or a public telephone switching network Accordingly, the traditional MS location difficulties, such as multipath, poor location accuracy and poor coverage are alleviated via such technologies in combination with strategies for: (a) automatically adapting and calibrating system performance according to environmental and geographical changes; (b) automatically capturing location signal data for continual enhancement of a self-maintaining historical data base retaining predictive location signal data; (c) evaluating MS locations according to both heuristics and constraints related to, eg, terrain, MS velocity and MS path extrapolation from tracking and (d) adjusting likely MS locations adaptively and statistically so that the system becomes progressively more comprehensive and accurate Further, the system can be modularly configured for use in location signaling environments ranging from urban, dense urban, suburban, rural, mountain to low traffic or isolated roadways Accordingly, the system is useful for 911 emergency calls, tracking, routing, people and animal location including applications for confinement to and exclusion from certain areas

Two phase local mobility scheme for wireless access to packet based networks

Abstract: Local mobility within a subnet is supported by classifying wireless base stations, and the routers used to forward packets to those base stations, within defined domains. Domains are defined to incorporate a subnet having a plurality of base stations. Base stations are used by mobile devices to attach to the wired portion of a packet-based network, such as the Internet, and exchange packets thereover with a correspondent node. Packets sent from the correspondent node to the mobile device have a packet destination address corresponding to the mobile device. The mobile device retains this address for the duration of time it is powered up and attached to the Internet via any base station within a given domain. Host-based routing is utilized to update routing table entries corresponding to the mobile device at routers incorporated within a single domain. The routing table entries are established and updated via path setup schemes to convey packets destined for the mobile device along the proper established path through the domain routers and base stations, regardless of the domain base station through which the mobile device is attached. Path setup schemes utilize power up, refresh, and handoff path setup messages to maintain the proper relationship between router interfaces and packet addresses for routing table entries.