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.

Vehicle locating and navigating system

Abstract: A vehicle locating and navigating system operating in conjunction with a cellular telephone network is provided. A small, hidden device located in a vehicle is activated through DTMF signals transmitted from any telephone station. Upon activation, the device determines the power at which normally transmitted control channels are received from several base stations of the network. Based upon these determinations, the device then calculates the distance between the vehicle and each of the base stations and, using triangulation or arculation, determines the location of the vehicle. The locational information is transmitted through a voice synthesizer back to the telephone station from which the activation signal is received, or to a different telephone station dedicated to receive this information. The locational information also is transmitted digitally to a central station where the position of the vehicle is displayed on a computer screen along with a graphical representation of a map of the region served by the cellular telephone network. An operator at the central station can assist the vehicle's operator with navigational information or provide tracking coordinates to a tracking vehicle equipped with a similar device.

Network supporting roaming, sleeping terminals

Abstract: Improved apparatus for a radio communication system having a multiplicity of mobile transceiver units selectively in communication with a plurality of base transceiver units which, in turn, communicate with one or more host computers for storage and manipulation of data collected by bar code scanners or other collection means associated with the mobile transceiver units. A network controller and an adapter which has a simulcast and sequential mode provide selective interface between host computers and base transceivers. A scheme for routing data through the communication system is also disclosed wherein the intermediate base stations are organized into an optimal spanning-tree network to control the routing of data to and from the RF terminals and the host computer efficiently and dynamically. Additionally, redundant network and communication protocol is disclosed wherein the network utilizes a polling communication protocol which, under heavy loaded conditions, requires that a roaming terminal wishing to initiate communication must first determine that the channel is truly clear by listing for an entire interpoll gap time. In a further embodiment, a criterion used by the roaming terminals for attaching to a given base station reduces conflicts in the overlapping RF regions of adjacent base stations.

Base-Station Assisted Device-to-Device Communications for High-Throughput Wireless Video Networks

Abstract: We propose a new scheme for increasing the throughput of video files in cellular communications systems This scheme exploits (1) the redundancy of user requests as well as (2) the considerable storage capacity of smartphones and tablets Users cache popular video files and-after receiving requests from other users-serve these requests via device-to-device localized transmissions The file placement is optimal when a central control knows a priori the locations of wireless devices when file requests occur However, even a purely random caching scheme shows only a minor performance loss compared to such a “genie-aided” scheme We then analyze the optimal collaboration distance, trading off frequency reuse with the probability of finding a requested file within the collaboration distance We show that an improvement of spectral efficiency of one to two orders of magnitude is possible, even if there is not very high redundancy in video requests

Sum power iterative water-filling for multi-antenna Gaussian broadcast channels

Abstract: We consider the problem of maximizing sum rate on a multiple-antenna downlink in which the base station and receivers have multiple-antennas. The optimum scheme for this system was recently found to be "dirty paper coding". Obtaining the optimal transmission policies of the users when employing this dirty paper coding scheme is a computationally complex nonconvex problem. We use a "duality" to transform this problem into a convex multiple access problem, and then obtain a simple and fast iterative algorithm that gives us the optimum transmission policies.

Multiple mode personal wireless communications system

Abstract: A multiple mode, personal, wireless communications system exists within a radiotelephone network serving general customers and provides additional services to a select group of customers. The system uses handsets (32) which automatically switch between a standard cellular radiotelephone mode of operation (1901) and an enhanced cordless mode (1420) when the handsets (32) are within range of pico cells (26) that are interconnected to the public switched telephone network (20). Each pico cell is controlled via a framework of overlay cells (10b) that operates independently of the radiotelephone network and uses a unique control protocol on a small number of reserved cellular channels. Each pico cell consists of a spectrally dynamic, non-capturing, frequency agile, multi-purpose base station (26) provided at customer-selected locations to cooperate with the overlay cell framework. Each pico cell is capable of supporting multiple handsets (32) and using low power operation that achieves limited coverage. Each pico cell reduces traffic on the standard cellular radiotelephone network by independently handling registered handsets (32). An alternate line option module (22) provides wireless local interconnect capability to selectively route call traffic between land lines (24) and the standard cellular radiotelephone network. Service control units (12) and host stations (17) facilitate wireless activation and control of each pico cell and handset (32) via the overlay cell framework.