Showing papers on "Wireless WAN published in 1999"

Next century challenges: scalable coordination in sensor networks

Abstract: Networked sensors-those that coordinate amongst themselves to achieve a larger sensing task-will revolutionize information gathering and processing both in urban environments and in inhospitable terrain. The sheer numbers of these sensors and the expected dynamics in these environments present unique challenges in the design of unattended autonomous sensor networks. These challenges lead us to hypothesize that sensor network coordination applications may need to be structured differently from traditional network applications. In particular, we believe that localized algorithms (in which simple local node behavior achieves a desired global objective) may be necessary for sensor network coordination. In this paper, we describe localized algorithms, and then discuss directed diffusion, a simple communication model for describing localized algorithms.

Critical Power for Asymptotic Connectivity in Wireless Networks

Abstract: In wireless data networks each transmitter’s power needs to be high enough to reach the intended receivers, while generating minimum interference on other receivers sharing the same channel. In particular, if the nodes in the network are assumed to cooperate in routing each others’ packets, as is the case in ad hoc wireless networks, each node should transmit with just enough power to guarantee connectivity in the network. Towards this end, we derive the critical power a node in the network needs to transmit in order to ensure that the network is connected with probability one as the number of nodes in the network goes to infinity. It is shown that if n nodes are placed in a disc of unit area in ℜ2 and each node transmits at a power level so as to cover an area of πr 2 = (log n + c(n))/n, then the resulting network is asymptotically connected with probability one if and only if c(n) → +∞.

Mobility management in next-generation wireless systems

Abstract: This paper describes current and proposed protocols for mobility management for public land mobile network (PLMN)-based networks, mobile Internet protocol (IP) wireless asynchronous transfer mode (ATM) and satellite networks. The integration of these networks will be discussed in the context of the next evolutionary step of wireless communication networks. First, a review is provided of location management algorithms for personal communication systems (PCS) implemented over a PLMN network. The latest protocol changes for location registration and handoff are investigated for mobile IP followed by a discussion of proposed protocols for wireless ATM and satellite networks. Finally, an outline of open problems to be addressed by the next generation of wireless network service is discussed.

Method and system for simultaneously sharing wireless communications among multiple wireless handsets

Abstract: A method and system for simultaneously sharing wireless communications among multiple wireless handsets deployed in a wireless network having at least one cell site associated therewith includes a first and second wireless handset for transmitting a request for the same wireless communication. The wireless network then assigns a first wireless receive channel to the first wireless handset and the second wireless handset and simultaneously transmits the requested wireless communication to the first and second wireless handsets for receipt by the first wireless receive channel. If the requested wireless communication originates from a source handset, and the first and second handsets are located in direct communication proximity to the source handset, the source handset itself negotiates the common wireless receive channel for receiving the requested wireless communication.

System and method for providing data to a wireless device upon detection of activity of the device on a wireless network

Abstract: A system and method of for exchanging information between a wireless network and an external system is disclosed. The wireless network detects trigger events related to communications with wireless subscribers. Certain event triggers cause the wireless system to create a message and to send that message to the external system. In response the external system may respond by sending data or information to the wireless system. The messages created by the wireless system may be in the form of query messages. The wireless system may create messages for the external system upon detection of handoff, origination, status, registration or other activity by the wireless subscriber.

Method and apparatus for wireless internet access

Abstract: A device for providing wireless Internet access has been described. The device includes an antenna. The antenna is for receiving wireless queries and transmitting wireless responses. The device includes a program. The program is for converting the wireless queries into Internet compatible protocols. The program is for receiving the Internet protocol formatted responses. These responses are then converted in to the wireless responses.

WTCP: a reliable transport protocol for wireless wide-area networks

Abstract: Wireless wide-area networks (WWANs) are characterized by very low and variable bandwidths, very high and variable delays, significant non-congestion related losses, asymmetric uplink and downlink channels, and occasional blackouts. Additionally, the majority of the latency in a WWAN connection is incurred over the wireless link. Under such operating conditions, most contemporary wireless TCP algorithms do not perform very well. In this paper, we present WTCP, a reliable transport protocol that addresses rate control and reliability over commercial WWAN networks such as CDPD. WTCP is rate-based, uses only end-to-end mechanisms, performs rate control at the receiver, and uses inter-packet delays as the primary metric for rate control. We have implemented and evaluated WTCP over the CDPD network, and also simulated it in the ns-2 simulator. Our results indicate that WTCP can improve on the performance of comparable algorithms such as TCP-NewReno, TCP-Vegas, and Snoop-TCP by between 20% to 200% for typical operating conditions.

Apparatus for interfacing a wireless local network and a wired voice telecommunications system

Abstract: An apparatus for interfacing a wireless local area network with a wide area, cellular or public switched telephone network including the function of a wireless LAN base station or access point, and a gateway. The interface may contain one or more different types of gateways, including a PSTN voice gateway, an analog modem gateway, and others. The apparatus may also include a well designed to receive the handset or mobile computer device to recharge the battery as well as to automatically transfer data when the phone or device is secured in the well.

Performance of a novel self-organization protocol for wireless ad-hoc sensor networks

Abstract: The paper presents an ad-hoc architecture for wireless sensor networks and other wireless systems similar to them. In this class of wireless system the physical resource at premium is energy. Bandwidth available to the system is in excess of system requirements. The approach to solve the problem of ad-hoc network formation here is to use available bandwidth in order to save energy. The method introduced solves the problem of connecting an ad-hoc network. This algorithm gives procedures for the joint formation of a time schedule (similar to a TDMA schedule) and activation of links therein for random network topologies. This self-organization method is energy-sensitive, distributed, scalable, and able to form a connected network rapidly.

Method and system for aiding GPS receivers via a cellular or PCS network

Abstract: In accordance with the invention, there is disclosed a system for determining location of a mobile station. The mobile station includes a transceiver operating in a wireless network and a GPS receiver. The system includes a wireless network control system including GPS receivers for obtaining ephemeris data. The control system develops assistance information from the ephemeris data and transmits the assistance information to the mobile station via the wireless network. The assistance information represents range at a fixed location in the wireless network in proximity to the mobile station at a select time, and derivatives of the range, relative to plural select satellites in the GPS. The mobile station utilizes received assistance information for searching the composite received signals from the plural select satellites in the GPS to measure a code phase for plural ones of the select satellites in the GPS and returning the measured code phases to the wireless network control system via the wireless network. The wireless network control system computes location of the mobile station in the wireless network utilizing a fixed location and the measured code phases.

Distributed management of an extended network containing short-range wireless links

Abstract: A method and apparatus for internetworked communication between first and second wireless networks containing first and second pluralities of wireless nodes, respectively, is disclosed herein. In a preferred implementation an internetworking node participates in both the first and second wireless networks, and receives a first set of network information identifying each of the first plurality of wireless nodes and the services offered thereby. The internetworking node is configured to transmit the first set of network information to a master node of the second wireless network. The internetworking node also receives, from the second wireless network, a second set of network information identifying each of the second plurality of wireless nodes and the services offered thereby. In addition, the internetworking node may also transmit the second set of network information to a master node of the first wireless network. The first master node may be configured to broadcast information relating to the services offered by each of the first plurality of wireless nodes and the second wireless network. Likewise, the second master node may be configured to broadcast information relating to the services offered by each of the second plurality of wireless nodes and the second wireless network. In a preferred embodiment each of the first plurality of wireless nodes transmits an advertisement to the first master node specifying its address and services offered thereby. Similarly, each of the second plurality of wireless nodes transmits an advertisement to the second master node specifying its address and services offered thereby.

Wireless multimedia player

Abstract: A wireless device, system and method for receiving and playing multimedia files streamed from a multimedia server over a wireless telecommunications network. A desired multimedia file is selected from one or more multimedia files stored in the multimedia server, which server is operatively connected to the wireless telecommunications network. Successive blocks of data from the desired multimedia file are streamed over the wireless telecommunications network in a digitized and compressed format and received by the wireless telecommunications device. The received blocks of data from the streamed multimedia file are temporarily stored in a buffer in the wireless device, decoded and decompressed, and successively played through an audio and/or video output in the wireless device. The wireless device monitors the blocks of data stored in the buffer and signals the wireless telecommunications network to increase the rate that the data blocks are transmitted over the wireless network in the event that the data stored in the buffer falls below a minimum threshold level.

Method and system for dynamic location-based zone assignment for a wireless communication network

Abstract: A method for dynamic location-based zone assignment for a wireless communication network is provided. The method utilizes the location of a user's wireless communication device relative to a number of network zones in the wireless communication network. The network zones and their respective coverage areas change from time-to-time. The method comprises receiving the location of the user's wireless communication device and accessing a geographical area definition of the user, wherein the geographical area definition includes at least one operating zone. The geographical area definition is translated to a current network area definition. The location of the user's wireless communication device is compared to the current network area definition in order to locate the user's wireless communication device relative to the operating zones. A record is then assigned based on which operating zone the user's wireless communication device is located.

Data rate algorithm for use in wireless local area networks

Abstract: A communications network comprising a wireless local area network includes a plurality of access points connected to a host computer and each other, and a plurality of mobile units with each mobile unit being arranged for association with at least one access point. The mobile units are arranged to periodically scan for and identify the most eligible access point for association at the highest data rate on the basis of a performance criteria at the current data rate.

Determination of Critical Transmission Range in Ad-Hoc Networks

Abstract: Ad-hoc networks are wireless mobile networks that do not rely on preexisting infrastructure. In such networks, multi-hop routing is used to achieve large degree of network connectivity and each node in the network acts as a router for its neighbors. The range of the radio transceivers is chosen as a trade-off between full network connectivity, the reuse of the available spectrum, and power consumption. This paper presents an algorithm to calculate the minimum transmission range of the transceivers that is required to achieve, with some probability, full network connectivity. Furthermore, we also study the effect of mobility on this value.

Method and apparatus for providing network access over different wireless networks

Abstract: The invention relates to centralized network access for wireless network carriers providing network access to wireless communication devices. The invention provides a network gateway (or proxy server) that provides access to a network of computers to various wireless network carriers having different wireless network characteristics. In one embodiment, the invention uses airlinks (or network drivers) to support the communications between the network gateway and the various wireless network carriers.

Any network, any terminal, anywhere [cellular radio]

Abstract: In light of the current technology trends in the area of applications, wireless networks, and terminals, this article isolates a number of design requirements of future advanced mobile systems. We discuss research and standardization activities in the area of service support platforms and their corresponding application programming interfaces (API), where we especially focus on the wireless application protocol (WAP), Mobile Station Execution Environment (MExE), and HTTP-NG as candidates for the provision of mobile Internet services in cellular networks.

Location-based information retrieval system for wireless communication device

Abstract: A wireless location-based information-retrieval system includes a wireless communication device. The wireless device has a transceiver for sending and receiving communications across a wireless communication network, a position-determination device for determining the location of the wireless device, and an Internet browser. A remote server communicates with the wireless device. The server receives the location data from the wireless device over the network and maintains a web page listing information service options. The information service options are accessible to and selectable by the wireless device via the browser. The server retrieves information from a database based on the location data provided by the wireless device and on the selected service option. The retrieved information is sent to the wireless device over the network.

Wireless access of packet based networks

Abstract: A General Packet Radio Service (GPRS) Accessed Extended Mobile Internet Protocol (EMIP) [G-EMIP] network is provided for wireless mobile device access to external packet data networks. Domains are defined to incorporate a subnet of standard GPRS and EMIP network entities accessed through a Domain Router. Packet access at the radio interface is provided using the base station portion of a GPRS network. Wireless link specific processing is relegated to this potion of the G-EMIP network. EMIP is utilized as a backbone network to provide mobility and service management and interconnection to external networks. A GPRS-IP Interworking entity (GII) interworks IP and GPRS protocols between GPRS and IP addressable network entities (i.e., translates messages of each protocol to corresponding messages of the other protocol). Mobility-related functionality is handled at the IP (network) layer. Mobile IP is used to support the macro-mobility and Handoff-Aware Wireless Access Internet Infrastructure (HAWAII) is used to support micro-mobility and paging. The Domain Router provides packet service management and interacts with a Home Location Register/Authentication Center, which provides GRPS registration, authentication and encryption.

Adaptive inverse multiplexing for wide-area wireless networks

Abstract: The limited bandwidth of current wide-area wireless access networks (WWANs) is often insufficient for demanding applications, such as streaming audio or video, data mining applications, or high-resolution imaging. Inverse multiplexing is a standard application-transparent method used to provide higher end-to-end bandwidth by splitting traffic across multiple physical links, creating a single logical channel. While commonly used in ISDN and analog dialup installations, current implementations are designed for private links with stable channel characteristics. Unfortunately, most WWAN technologies use shared channels with highly variable link characteristics, including bandwidth, latency, and loss rates. This paper presents an adaptive inverse multiplexing scheme for WWAN environments, termed link quality balancing, which uses relative performance metrics to adjust traffic scheduling across bundled links. By exchanging loss rate information, we compute relative short-term available bandwidths for each link. We discuss the challenges of adaptation in a WWAN network, CDPD in particular, and present performance measurements of our current implementation of wide-area multi-link PPP (WAMP) for CDPD modems under both constant bit rate (CBR) and TCP loads.

Wireless telemetry methods and systems for communicating with or controlling intelligent devices

Abstract: Methods and apparatus are disclosed for remotely monitoring and controlling via a wireless network various devices deployed in homes and businesses. The present invention allows for monitoring and control of various gateways distributed to remotely located facilities to be monitored and the devices coupled to those gateways to be controlled via a wireless communications network. Preferably, the network is a GSM network adapted to provide short messaging services or any type of wireless network adapted to operate a General Packet Radio System for delivering data over the network. Messages are packaged at each gateway for delivery via the network to a destination terminal, whether a fixed terminal or a mobile station. Likewise, customers may forward data and commands to a particular gateway either from a mobile station or by accessing a fixed terminal, such as through an Internet connection. Transporting messages or commands via the short messaging service of the GSM network or via the GPRS protocol avoids the prohibitive cost of setting up a call for each message and avoids the significant capital costs needed to set up a separate communication network for data delivery.

Dynamic channel reservation based on mobility in wireless ATM networks

Abstract: We present a dynamic channel reservation scheme to improve the utilization of wireless network resources while guaranteeing the required QoS of handoff calls. The wireless channels are dynamically reserved by using the request probability determined by the mobility characteristics and channel occupancy to guarantee acceptable quality of handoff calls and keep the new call blocking probability as low as possible.

Analysis of a metropolitan-area wireless network

Abstract: We analyze a seven-week trace of the Metricom metropolitan-area packet radio wireless network to find how users take advantage of a mobile environment. Such understanding is critical for planning future large-scale mobile network infrastructures. Amongst other results, we find that users typically use the radios during the day and evening. Of the users who move around during the trace (over half), we find that the more locations a user visits on a daily basis, the closer together, on average, those locations are. While these results are only known to be valid for this particular network, we hope future analysis of other networks will add to a growing understanding of mobile network behavior.

Advances in wireless terminals

Abstract: The current wireless networks are being replaced by emerging wireless networking technologies that are intrinsically designed to support packet data and multimedia services. This will lead to novel networked applications and services, which in turn will require wireless terminals capable of exploiting these services. What shape will these next-generation wireless terminals take? The answer, based on the much talked about notion of "convergence", would appear to be a marriage of the laptop or PC with a wireless phone in the same package. We argue that such a complex one-size-fits-all voice-data integrated wireless terminal will, at best, be a point solution. Rather, with the availability of cheap radio and computing hardware and ubiquitous low-cost indoor and outdoor wireless networking infrastructures, the capability to access a wireless network will soon be embedded into a variety of devices, gadgets, and appliances with specialized functions in our environment. In this article we describe the technological challenges and identify potential solutions in designing these myriad future "wireless terminals" that will handle diverse data types, have limited battery resources, and operate in environments that are unplanned, insecure, and time-varying, and have context-dependent services.

Method and arrangement for wireless communication by means of at least two network computers

Abstract: An arrangement and a method with which wireless terminal devices which can usually be reached via a call number of one individual network computer can also be reached when they are located in the wireless communication area of a base station that is connected to another network computer. To this end, connection information is retrieved via a mobility server, and a connection setup to a corresponding network computer in whose radio area the wireless terminal device is located is controlled via that mobility server. The wireless terminal device delivers information, which is transmitted to the mobility server and from which, together with additional information from the network computer or the base station, this server is able to derive the information for the connection setup to the wireless terminal device. In order to limit the utilized network computers to only a switching function, performance features of the wireless terminal device are realized via a performance feature server, which controls the corresponding network computer via a CTI interface. The mobility servers are likewise connected to the respective network computers via a CTI interface. In this way, it is possible to realize private wireless communication networks with DECT functionality and with a large coverage, in which networks it is possible to reach wireless terminal devices at will, though they are dialed simply via the call number of a single network computer allocated to them.

Wireless universal provisioning device

Abstract: A system includes at least one wireless communications device having a standard wireless interface and a wireless provisioning device that provisions the wireless communications device. The wireless provisioning device uses the standard wireless interface to transfer the provisioning information, including an authentication key, to the wireless communications device when both devices are interconnected via a wireline link between a transceiver antenna of the wireless communications device and a communication unit of the provisioning device.

User Location and Tracking in an In-Building Radio Network

Abstract: The proliferation of mobile computing devices and local-area wireless networks has fostered a growing interest in location-aware systems and services A key requirement for enabling such services is user location and tracking In this paper we address this problem in the context of a popular radio-frequency wireless network technology Our approach is based on recording and processing real-time signal strength information available at multiple base stations positioned to provide overlapping coverage in the area of interest We employ techniques that combine empirical measurements with signal propagation modeling We present concrete experimental results that demonstrate the feasibility of estimating user location with a high degree of accuracy

Cellular mobile telephone network operation

Abstract: Where a call of one cellular telephone network has a cell of another network as neighbor, a dedicated control channel for a mobile station which is registered with the public network and whose subscriber has access privileges for the private network, carries neighboring cell data for the cell of the private network. Consequently, the mobile station (provides measurement reports for cells of both network and can be preferentially handed over to the cell of the private network by the public network.

Multi-level encryption system for wireless network

Abstract: A multi-level encryption scheme is provided for a wireless network. A first level of encryption is provided primarily for wireless communications taking place between a mobile terminal and an access point. In addition, a second, higher level of encryption is provided which is distributed beyond the wireless communications onto the system backbone itself. Through a key distribution server/access point arrangement, the second level of encryption provides a secure means for distributing the encryption scheme of the first level without compromising the integrity of the network.

Broadband wireless mesh topology network

Abstract: A broadband wireless network based on mesh topology, optimized for delivery of data, Internet, voice and multimedia to consumers, small offices and large company premises using data interfaces such as the IP standard interface and consumer multimedia digital bus interface (BAP-1, BAP-2). a customer premises wireless transceivers (SR10-SR21) with the ability of adding and dropping data via standard interface as well as routing data between multiple wireless nodes using route diversity enhances the mesh network availability, reliability and allows load balancing.