Showing papers on "Cellular network published in 2006"

Network coordination for spectrally efficient communications in cellular systems

Abstract: In this article we consider network coordination as a means to provide spectrally efficient communications in cellular downlink systems. When network coordination is employed, all base antennas act together as a single network antenna array, and each mobile may receive useful signals from nearby base stations. Furthermore, the antenna outputs are chosen in ways to minimize the out-of-cell interference, and hence to increase the downlink system capacity. When the out-of-cell interference is mitigated, the links can operate in the high signal-to-noise ratio regime. This enables the cellular network to enjoy the great spectral efficiency improvement associated with using multiple antennas

A tutorial on cross-layer optimization in wireless networks

Abstract: This tutorial paper overviews recent developments in optimization-based approaches for resource allocation problems in wireless systems. We begin by overviewing important results in the area of opportunistic (channel-aware) scheduling for cellular (single-hop) networks, where easily implementable myopic policies are shown to optimize system performance. We then describe key lessons learned and the main obstacles in extending the work to general resource allocation problems for multihop wireless networks. Towards this end, we show that a clean-slate optimization-based approach to the multihop resource allocation problem naturally results in a "loosely coupled" cross-layer solution. That is, the algorithms obtained map to different layers [transport, network, and medium access control/physical (MAC/PHY)] of the protocol stack, and are coupled through a limited amount of information being passed back and forth. It turns out that the optimal scheduling component at the MAC layer is very complex, and thus needs simpler (potentially imperfect) distributed solutions. We demonstrate how to use imperfect scheduling in the cross-layer framework and describe recently developed distributed algorithms along these lines. We conclude by describing a set of open research problems

Coordinating multiple antenna cellular networks to achieve enormous spectral efficiency

Abstract: Intercell interference limits the capacity of wireless networks. To mitigate this interference we explore coherently coordinated transmission (CCT) from multiple base stations to each user. To treat users fairly, we explore equal rate (ER) networks. We evaluate the downlink network efficiency of CCT as compared to serving each user with single base transmission (SBT) with a separate base uniquely assigned to each user. Efficiency of ER networks is measured as total network throughput relative to the number of network antennas at 10% user outage. Efficiency is compared relative to the baseline of single base transmission with power control, (ER-SBT), where base antenna transmissions are not coordinated and apart from power control and the assignment of 10% of the users to outage, nothing is done to mitigate interference. We control the transmit power of ER systems to maximise the common rate for ER-SBT, ER-CCT based on zero forcing, and ER-CCT employing dirty paper coding. We do so for (no. of transmit antennas per base, no. of receive antennas per user) equal to (1,1), (2,2) and (4,4). We observe that CCT mutes intercell interference enough, so that enormous spectral efficiency improvement associated with using multiple antennas in isolated communication links occurs as well for the base-to-user links in a cellular network.

Environmental Monitoring by Wireless Communication Networks

Abstract: The global spread of wireless networks brings a great opportunity for their use in environmental studies. Weather, atmospheric conditions, and constituents cause propagation impairments on radio links. As such, while providing communication facilities, existing wireless communication systems can be used as a widely distributed, high-resolution atmospheric observation network, operating in real time with minimum supervision and without additional cost. Here we demonstrate how measurements of the received signal level, which are made in a cellular network, provide reliable measurements for surface rainfall. We compare the estimated rainfall intensity with radar and rain gauge measurements.

A cross-layer scheduling algorithm with QoS support in wireless networks

Abstract: Scheduling plays an important role in providing quality of service (QoS) support to multimedia communications in various kinds of wireless networks, including cellular networks, mobile ad hoc networks, and wireless sensor networks. The authors propose a scheduling algorithm at the medium access control (MAC) layer for multiple connections with diverse QoS requirements, where each connection employs adaptive modulation and coding (AMC) scheme at the physical (PHY) layer over wireless fading channels. Each connection is assigned a priority, which is updated dynamically based on its channel and service status; the connection with the highest priority is scheduled each time. The authors' scheduler provides diverse QoS guarantees, uses the wireless bandwidth efficiently, and enjoys flexibility, scalability, and low implementation complexity. Its performance is evaluated via simulations

Locating system and method

Abstract: A mobile rover has a navigation receiver receiving radio positioning data from radio positioning entities. The mobile rover can report its position to a mobile controller unit or another entity so that the location of the mobile unit can be tracked based on the radio positioning data received by the mobile rover. The radio positioning data can be processed by processing systems within the mobile rover, mobile controller, or other entities such as a position determination entity or a position determination entity proxy. The processing systems can also perform calculations to augment the radio positioning data to provide more accurate estimates of the position of the mobile controller and/or the mobile rover. The mobile controller and/or the mobile rover may be cellular telephones within a cellular network.

Joint Optimization of Relay Strategies and Resource Allocations in Cooperative Cellular Networks

Abstract: This paper considers a wireless cooperative cellular data network with a base station and many subscribers in which the subscribers have the ability to relay information for each other to improve the overall network performance. For a wireless network operating in a frequency-selective fading environment, the choices of relay node, relay strategy, and the allocation of power and bandwidth for each user are important design parameters. The design challenge is compounded further by the need to take user traffic demands into consideration. This paper proposes a utility maximization framework for such a network. We show that for a cellular system employing orthogonal frequency-division multiple-access (OFDMA), the optimization of physical layer transmission strategies can be done efficiently by introducing a set of pricing variables. The proposed solution incorporates both user traffic demand and the physical channel realization in a cross-layer design that not only allocates power and bandwidth optimally for each user, but also selects the best relay node and best relay strategy (i.e, decode-and-forward vs. amplify-and-forward) for each source-destination pair.

A new networking model for biological applications of ad hoc sensor networks

Abstract: In this paper, we introduce the Shared Wireless Infostation Model (SWIM), which extends the Infostation model by incorporating information replication, storage, and diffusion into a mobile ad hoc network architecture with intermittent connectivity. SWIM is able to reduce the delay of packet delivery at the expense of increased storage at the network nodes. Furthermore, SWIM improves the overall capacity-delay tradeoff by only moderately increasing the storage requirements. This tradeoff is examined here in the context of a practical application-acquisition of telemetry data from radio-tagged whales. To reduce the storage requirements, without affecting the network delay, we propose and study a number of schemes for deletion of obsolete information from the network nodes. In particular, through the use of Markov chains, we compare the performance of five such storage deletion schemes, which, by increasing the computational complexity of the routing algorithm, mitigate the storage requirements. The results of our study will allow a network designer to implement such a system and to tune its performance in a delay-tolerant environment with intermittent connectivity, as to ensure with some chosen level of confidence that the information is successfully carried through the mobile network and delivered within some time period.

Code torrent: content distribution using network coding in VANET

Abstract: Mobile peer-to-peer systems have recently got in the lime-light of the research community that is striving to build efficient and effective mobile content addressable networks. Along this line of research, we propose a network coding based file swarming protocol targeting vehicular ad hoc net-works (VANET). We argue that file swarming protocols in VANET should deal with typical mobile network issues such as dynamic topology and intermittent connectivity as well as various other issues that have been disregarded in previous mobile peer-to-peer researches such as addressing, node/user density, non-cooperativeness, and unreliable channel. Through simulation, we show that the efficiency and effectiveness of our protocol allows shorter file downloading time compared to an existing VANET file swarming protocol.

Efficient in-network moving object tracking in wireless sensor networks

Abstract: The rapid progress of wireless communication and embedded microsensing MEMS technologies has made wireless sensor networks possible In light of storage in sensors, a sensor network can be considered as a distributed database, in which one can conduct in-network data processing An important issue of wireless sensor networks is object tracking, which typically involves two basic operations: update and query This issue has been intensively studied in other areas, such as cellular networks However, the in-network processing characteristic of sensor networks has posed new challenges to this issue In this paper, we develop several tree structures for in-network object tracking which take the physical topology of the sensor network into consideration The optimization process has two stages The first stage tries to reduce the location update cost based on a deviation-avoidance principle and a highest-weight-first principle The second stage further adjusts the tree obtained in the first stage to reduce the query cost The way we model this problem allows us to analytically formulate the cost of object tracking given the update and query rates of objects Extensive simulations are conducted, which show a significant improvement over existing solutions

Statistical properties of amplify and forward relay fading channels

Abstract: Cooperation diversity schemes have been proposed for cellular networks that permit mobile stations to relay signals to a final destination, thereby increasing the network capacity and coverage. The mobile relays either decode and retransmit the received signal or simply amplify and forward (A & F) the signal. The overall channel from the source to the destination via the relay in A & F systems is "double" Gaussian with properties quite different from a typical cellular channel. Since very little is known about A & F relay fading channels, this paper considers their statistical properties such as the envelope probability density function, autocorrelation, level crossing rate, and system performance characteristics like frequency of outages and average outage durations. We briefly discuss the simulation of these channels and verify our analysis by simulations.

Methods and apparatus for selecting a communication network

Abstract: Methods and apparatus for selecting a cellular network to provide one or more communication services for a mobile communication device are disclosed. A scanning operation is performed by the mobile device to identify a plurality of cellular networks that support a voice communication service in a geographic coverage area. The mobile device then identifies which of the cellular networks makes a data communication service available to it. Advantageously, the mobile device assigns priority to or selects a cellular network that makes the data communication service available over a network that fails to make the data communication service available, and may register with that network. The data communication service may include, as examples, an e-mail communication service or an Internet access service. Preferably, the cellular network operates in accordance with GSM (Global System for Mobile) and GPRS (Generalized Packet Radio Service).

Method of transmitting and receiving radio access information in a wireless mobile communications system

Abstract: In a wireless mobile communications system, a method of transmitting and receiving radio access information that allows a faster and an efficient way of establishing a radio connection between a terminal and a target base station while performing a handover for the terminal to a cell of the target base station. The network transmits in advance, the radio access information and the like, to the terminal so that the terminal can be connected with the target cell in a faster manner which minimizes the total time for the handover process.

Call admission control in mobile cellular networks: a comprehensive survey

Abstract: Call admission control (CAC) is a key element in the provision of guaranteed quality of service (QoS) in wireless networks. The design of CAC algorithms for mobile cellular networks is especially challenging given the limited and highly variable resources, and the mobility of users encountered in such networks. This article provides a survey of admission control schemes for cellular networks and the research in this area. Our goal is to provide a broad classification and thorough discussion of existing CAC schemes. We classify these schemes based on factors such as deterministic/stochastic guarantees, distributed/local control and adaptivity to traffic conditions. In addition to this, we present some modeling and analysis basics to help in better understanding the performance and efficiency of admission control schemes in cellular networks. We describe several admission control schemes and compare them in terms of performance and complexity. Handoff prioritization is the common characteristic of these schemes. We survey different approaches proposed for achieving handoff prioritization with a focus on reservation schemes. Moreover, optimal and near-optimal reservation schemes are presented and discussed. Also, we overview other important schemes such as those designed for multi-service networks and hierarchical systems as well as complete knowledge schemes and those using pricing for CAC. Finally, the paper concludes on the state of current research and points out some of the key issues that need to be addressed in the context of CAC for future cellular networks. Copyright © 2005 John Wiley & Sons, Ltd.

Advanced Cellular Network Planning and Optimisation: 2G/2.5G/3G...Evolution to 4G

Abstract: A highly practical guide rooted in theory to include the necessary background for taking the reader through the planning, implementation and management stages for each type of cellular network. Present day cellular networks are a mixture of the technologies like GSM, EGPRS and WCDMA. They even contain features of the technologies that will lead us to the fourth generation networks. Designing and optimising these complex networks requires much deeper understanding. Advanced Cellular Network Planning and Optimisation presents radio, transmission and core network planning and optimisation aspects for GSM, EGPRS and WCDMA networks with focus on practical aspects of the field. Experts from each of the domains have brought their experiences under one book making it an essential read for design practitioners, experts, scientists and students working in the cellular industry. Key Highlights * Focus on radio, transmission and core network planning and optimisation * Covers GSM, EGPRS, WCDMA network planning & optimisation * Gives an introduction to the networks/technologies beyond WCDMA, and explores its current status and future potential * Examines the full range of potential scenarios and problems faced by those who design cellular networks and provides advice and solutions all backed up with real-world examples This text will serve as a handbook to anyone engaged in the design, deployment, performance and business of Cellular Networks. "Efficient planning and optimization of mobile networks are key to guarantee superior quality of service and user experience. They also form the essential foundation for the success of future technology development, making this book a valuable read on the road towards 4G." -Tero Ojanpera, Chief Technology Officer, Nokia Networks

Scaling results on the sum capacity of cellular networks with MIMO links

Abstract: Scaling results for the sum capacity of the multiple access, uplink channel are provided for a flat-fading environment, with multiple-input-multiple-output (MIMO) links, when there is interference from other cells. The classical MIMO scaling regime is considered in which the number of antennas per user and per base station grow large together. Utilizing the known characterizations of the limiting eigenvalue distributions of large random matrices, the asymptotic behavior of the sum capacity of the system is characterized for an architecture in which the base stations cooperate in the joint decoding process of all users (macrodiversity). This asymptotic sum capacity is compared with that of the conventional scenario in which the base stations only decode the users in their cells. For the case of base station cooperation, an interesting "resource pooling" phenomenon is observed: in some cases, the limiting performance of a macrodiversity multiuser network has the same asymptotic behavior as that of a single-user MIMO link with an equivalent amount of pooled received power. This resource pooling phenomenon allows us to derive an elegant closed-form expression for the sum capacity of a new version of Wyner's classical model of a cellular network, in which MIMO links are incorporated into the model.

Mobile telephone VOIP/cellular seamless roaming switching controller

Abstract: A nomadic server and a related system provides seamless roaming for a mobile communication device between different types of wireless networks, such as WiFi and cellular networks for voice, data and video communication. Use of the nomadic server enables a combination of WiFi and cellular networks for providing access to the cellular phones and make use of the VOIP networks for switching the calls wherever possible. The nomadic server is a telephone communication processing and switching server that will “hold” the present, in-progress telephone communications without dropping, while roaming without losing the present, in-progress communication. For example, a telephone communication can be seamlessly switching between VOIP and cellular telephone networks using the nomadic server. Nomadic server resources interface with the VOIP and cellular network switches to provide the hand-off between networks. This approach enables switching of telephone communications over a VOIP network wherever possible either through WiFi or through cellular networks.

Robust Mobile Location Estimator with NLOS Mitigation using Interacting Multiple Model Algorithm

Abstract: A Kalman-based interacting multiple model (IMM) smoother is proposed for mobile location estimation with the time of arrival (TOA) measurement data in cellular networks to meet the Federal Communications Commission (FCC) requirement for phase 2. In this study, the line-of-sight (LOS) and non-line-of-sight (NLOS) conditions in cellular networks are considered as a Markov process with two interactive modes. Then we propose a Kalman-based IMM smoother to accurately estimate smooth range between the corresponding base station (BS) and mobile station (MS) in cellular networks. It is shown that the proposed mobile location estimator can efficiently mitigate the NLOS effects of the measurement range error even when the corresponding BS changes the condition between LOS and NLOS. Simulation results demonstrate that the performance of the proposed Kalman-based IMM smoother is improved significantly over the FCC target in both fixed LOS/NLOS and LOS/NLOS transition conditions

Positioning Algorithms for Cellular Networks Using TDOA

Abstract: In this paper, we investigate the performance of positioning algorithms in wireless cellular networks based on time difference of arrival (TDoA) measurements provided by the base stations. The localization process of the mobile station results in a non-linear least squares estimation problem which cannot be solved analytically. Therefore, we use iterative algorithms to determine an estimate of the mobile station position. The well-known Gauss-Newton method fails to converge for certain geometric constellations, and thus, it is not suitable for a general solution in cellular networks. Another algorithm is the steepest descent method which has a slow convergence in the final iteration steps. Hence, we apply the Levenberg-Marquardt algorithm as a new approach in the cellular network localization framework. We show that this method meets the best trade-off between accuracy and computational complexity.

Method and apparatus for wireless multi-carrier communications

Abstract: A Global System for Mobile Communications (GSM) network supports multi-carrier operation on the downlink and/or uplink for a mobile station. The mobile station receives an assignment of multiple carriers for a first link in the GSM network, receives an assignment of at least one carrier for a second link in the GSM network, and exchanges data with the GSM network via the multiple carriers for the first link and the at least one carrier for the second link. The first link may be the downlink and the second link may be the uplink, or vice versa. The mobile station may receive data on multiple carriers at the same time for multi-carrier operation on the downlink. The mobile station may transmit data on multiple carriers at the same time for multi-carrier operation on the uplink.

Exploiting MMS Vulnerabilities to Stealthily Exhaust Mobile Phone's Battery

Abstract: As cellular data services and applications are being widely deployed, they become attractive targets for attackers, who could exploit unique vulnerabilities in cellular networks, mobile devices, and the interaction between cellular data networks and the Internet. In this paper, we demonstrate such an attack, which surreptitiously drains mobile devices' battery power up to 22 times faster and therefore could render these devices useless before the end of business hours. This attack targets a unique resource bottleneck in mobile devices (the battery power) by exploiting an insecure cellular data service (MMS) and the insecure interaction between cellular data networks and the Internet (PDP context retention and the paging channel). The attack proceeds in two stages. In the first stage, the attacker compiles a hit list of mobile devices ? including their cellular numbers, IP addresses, and model information ? by exploiting MMS notification messages. In the second stage, the attacker drains mobile devices' battery power by sending periodical UDP packets and exploiting PDP context retention and the paging channel. This attack is unique not only because it exploits vulnerable cellular services to target mobile devices but also because the victim mobile users are unaware when their batteries are being drained. Furthermore, we identify two key vulnerable components in cellular networks and propose mitigation strategies for protecting cellular devices from such attacks from the Internet.

Private Access Point Containing a Sim Card

Abstract: An access point, or base station, for a mobile communications network, such as a cellular communications network, can be installed by a user, for use within or close to their own home or office. The base station has a SIM card, and can establish secure communications with the core network of the mobile communications network over the user’s existing broadband internet connection. The base station is also able to obtain the necessary ciphering keys, in order to allow the mobile device to communicate securely with the base station, and hence with the core network.

The Global In-Flight Internet

Abstract: In this paper, the concept of a new form of mobile network formed in the sky is introduced, where the mobile routers are simply the commercial aircraft. This implementation aims to eliminate two main problems arising from the current in-flight broadband implementation. The first problem is the resource management issue that may arise from the rapid increase of in-flight broadband Internet use in the near future. This could consequently limit current satellite resources, and bandwidth. The other issue is the inherent problem associated with Internet use over satellite, such as the degraded performance of delay sensitive applications due to the long propagation delay of a satellite link. A system model for data access, stable clustering of aircraft, and efficient routing schemes are introduced, which are suitable for the aeronautical mobility model. Link stability is predicted by a novel approach using Doppler shift subjected to control packets to dynamically form stable clustering and routing protocols. Another aim of this paper is to show that relative velocity between nodes is adequate as a stability metric, dominating relative distance, and this becomes evident in the simulations presented. An outline of how the new system could potentially interact with the traditional Internet using Mobile IP is also briefly discussed

Predictability of WLAN Mobility and Its Effects on Bandwidth Provisioning

Abstract: Wireless local area networks (WLANs) are emerging as a popular technology for access to the Internet and enterprise networks. In the long term, the success of WLANs depends on services that support mobile network clients. Although other researchers have explored mobility prediction in hypothetical scenarios, evaluating their predictors analytically or with synthetic data, few studies have been able to evaluate their predictors with real user mobility data. As a first step towards filling this fundamental gap, we work with a large data set collected from the Dartmouth College campus-wide wireless network that hosts more than 500 access points and 6,000 users. Extending our earlier work that focuses on predicting the next-visited access point (i.e., location), in this work we explore the predictability of the time of user mobility. Indeed, our contributions are two-fold. First, we evaluate a series of predictors that reflect possible dependencies across time and space while benefiting from either individual or group mobility behaviors. Second, as a case study we examine voice applications and the use of handoff prediction for advance bandwidth reservation. Using application-specific performance metrics such as call drop and call block rates, we provide a picture of the potential gains of prediction. Our results indicate that it is difficult to predict handoff time accurately, when applied to real campus WLAN data. However, the findings of our case study also suggest that application performance can be improved significantly even with predictors that are only moderately accurate. The gains depend on the applications’ ability to use predictions and tolerate inaccurate predictions. In the case study, we combine the real mobility data with synthesized traffic data. The results show that intelligent prediction can lead to significant reductions in the rate at which active calls are dropped due to handoffs with marginal increments in the rate at which new calls are blocked.

Scaling Results on the Sum Capacity of Cellular Networks

Abstract: — Scaling results for the sum capacity of the multiple access,uplink channel are provided for a flat-fading environment, with mul-tiple-input–multiple-output (MIMO) links, when there is interferencefrom other cells. The classical MIMO scaling regime is considered inwhich the number of antennas per user and per base station grow largetogether. Utilizing the known characterizations of the limiting eigenvaluedistributions of large random matrices, the asymptotic behavior of thesum capacity of the system is characterized for an architecture in whichthe base stations cooperate in the joint decoding process of all users(macrodiversity). This asymptotic sum capacity is compared with thatof the conventional scenario in which the base stations only decode theusers in their cells. For the case of base station cooperation, an interesting“resource pooling” phenomenon is observed: in some cases, the limitingperformance of a macrodiversity multiuser network has the same asymp-totic behavior as that of a single-user MIMO link with an equivalentamount of pooled received power. This resource pooling phenomenonallows us to derive an elegant closed-form expression for the sum capacityof a new version of Wyner’s classical model of a cellular network, in whichMIMO links are incorporated into the model.

Integrated Radio Resource Allocation for Multihop Cellular Networks With Fixed Relay Stations

Abstract: Recently, the notion that a logical next step towards future mobile radio networks is to introduce multihop relaying into cellular networks, has gained wide acceptance. Nevertheless, due to the inherent drawbacks of multihop relaying, e.g., the requirement for extra radio resources for relaying hops, and the sensitivity to the quality of relaying routes, multihop cellular networks (MCNs) require a well-designed radio resource allocation strategy in order to secure performance gains. In this paper, the optimal radio resource allocation problem in MCNs, with the objective of throughput maximization, is formulated mathematically and proven to be NP-hard. Considering the prohibitive complexity of finding the optimal solution for such an NP-hard problem, we propose an efficient heuristic algorithm, named integrated radio resource allocation (IRRA), to find suboptimal solutions. The IRRA is featured as a low-complexity algorithm that involves not only base station (BS) resource scheduling, but also routing and relay station (RS) load balancing. Specifically, a load-based scheme is developed for routing. A mode-aware BS resource-scheduling scheme is proposed for handling links in different transmission modes, i.e., direct or multihop. Moreover, a priority-based RS load balancing approach is presented for the prevention of the overloading of RSs. Within the framework of the IRRA, the above three functions operate periodically with coordinated interactions. To prove the effectiveness of the proposed IRRA algorithm, a case study was carried out based on enhanced uplink UMTS terrestrial radio access/frequency-division duplex with fixed RSs. The IRRA is evaluated through system level simulations, and compared with two other cases: 1) nonrelaying and 2) relaying with a benchmark approach. The results show that the proposed algorithm can ensure significant gains in terms of cell throughput

Cell Breathing Techniques for Load Balancing in Wireless LANs

Abstract: Maximizing network throughput while providing fairness is one of the key challenges in wireless LANs (WLANs). This goal is typically achieved when the load of access points (APs) is balanced. Recent studies on operational WLANs, however, have shown that AP load is often substantially uneven. To alleviate such imbalance of load, several load balancing schemes have been proposed. These schemes commonly require proprietary software or hardware at the user side for controlling the user-AP association. In this paper we present a new load balancing technique by controlling the size of WLAN cells (i.e., AP’s coverage range), which is conceptually similar to cell breathing in cellular networks. The proposed scheme does not require any modification to the users neither the IEEE 802.11 standard. It only requires the ability of dynamically changing the transmission power of the AP beacon messages. We develop a set of polynomial time algorithms that find the optimal beacon power settings which minimize the load of the most congested AP. We also consider the problem of network-wide min-max load balancing. Simulation results show that the performance of the proposed method is comparable with or superior to the best existing association-based methods.

Genetic Approach for Network Planning in the RFID Systems

Abstract: The problem of choosing the optimum locations for readers (antennas) in a RFID communications system is considered. All these choices must satisfy a set of imperative constraints and optimize a set of objectives. The factors affecting optimum selection are the complex propagation environments, the undesired mutual coverage and the unavoidable interference of multiple readers. Unlike the antenna positioning in traditional cellular networks, uplink signals, i.e. signals from tag towards reader, must be taken into account when dealing with the planning in the RFID networks. This paper presents a genetic approach for tackling this complex optimization problem. To validate this approach, computational results are presented for a typical test scenario.

Methods, systems and computer products for remote monitoring and control of application usage on mobile devices

Abstract: Methods, systems and computer products for notifying a customer if particular telephone numbers are in communication with the mobile network, and when a particular application associated with the telephone numbers are in use. Exemplary embodiments include a methods, systems and computer products for providing a mobile network notification service, including establishing a notification relationship between a device and the mobile network, monitoring the device for application usage on the network, generating a notification on the network related to the application usage and in response to the notification, generating a response to the application usage.

Distributed Uplink Power Control for Optimal SIR Assignment in Cellular Data Networks

Abstract: This paper solves the joint power control and SIR assignment problem through distributed algorithms in the uplink of multi-cellular wireless networks. The 1993 Foschini–Miljanic distributed power control can attain a given fixed and feasible SIR target. In data networks, however, SIR needs to be jointly optimized with transmit powers in wireless data networks. In the vast research literature since the mid-1990s, solutions to this joint optimization problem are either distributed but suboptimal, or optimal but centralized. For convex formulations of this problem, we report a distributed and optimal algorithm. The main issue that has been the research bottleneck is the complicated, coupled constraint set, and we resolve it through a re-parametrization via the left Perron Frobenius eigenvectors, followed by development of a locally computable ascent direction. A key step is a new characterization of the feasible SIR region in terms of the loads on the base stations, and an indication of the potential interference from mobile stations, which we term spillage. Based on this load-spillage characterization, we first develop a distributed algorithm that can achieve any Pareto-optimal SIR assignment, then a distributed algorithm that picks out a particular Pareto-optimal SIR assignment and the associated powers through utility maximization. Extensions to power-constrained and interference-constrained cases are carried out. The algorithms are theoretically sound and practically implementable: we present convergence and optimality proofs as well as simulations using 3GPP network and path loss models.