| 1. |
- Ahlin, Lars, et al.
(författare)
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Automous tactical communication : problems & possibilities
- 1996
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Konferensbidrag (refereegranskat)abstract
- On the battlefield of the future, more and more information will be available for making decisions on a tactical level, provided that this information can be dispersed rapidly and accurately. Sophisticated electronic equipment for communication, information processing and for collection of sensor data are becoming light-weight, small and inexpensive. As a consequence, advanced tactical decision support that now is limited to advanced platforms (e.g. combat aircrafts) will become available at a much lower level, maybe down to the individual soldier. In such a scenario, the number of communicating entities is one or several orders of magnitude larger than in todays tactical systems. Establishing reliable wireless communications in such a large group constitutes a considerable engineering challenge. In this paper we investigate the specific engineering challenges and the fundamental limitations of such low level, autonomous communication systems. Our conclusions are that mainly distributed computing complexity, device power consumption and available bandwidth constitute the fundamental problems.
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| 2. |
- Ahlin, Lars, et al.
(författare)
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Automous Tactical Communications Possibilities and Problems
- 1997
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Ingår i: MILCOM 97 Proceedings. - 0780342496 ; , s. 393-397
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Konferensbidrag (refereegranskat)abstract
- In the battlefield of the future, more and more information will be available for making decisions on a tactical level, provided that this information can be dispersed rapidly and accurately. As a consequence, advanced tactical decision support that now is limited to advanced platforms (e.g. combat aircrafts) will become available at a much lower level, ranging from different kinds of vehicles, down to the individual soldier by means of ultra-light weight ``wearable'' equipment. Establishing reliable wireless communications in such a large group of users with unprecidented bandwidth demands and requirements on survivability constitutes a considerable enginerring challenge. In the paper we will, after a short review of some existing approaches, investigate the specific engineering challenges and the fundamental limitations of such low level, autonomous communication systems. Further we give an example of a system architecture, harmonized with a proposed structure for third generation commercial wireless systems (e.g. UMTS). Our conclusions show that mainly distributed computing complexity, device power consumption and available bandwidth constitute the fundamental problems.
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| 3. |
- Andersin, Michael, et al.
(författare)
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Gradual removals in cellular PCS with constrained power control and noise
- 1995
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Ingår i: IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC. - 0780330021 ; , s. 56-60
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Konferensbidrag (refereegranskat)abstract
- In this paper we study the mobile removal problem in a cellular PCS network where transmitter powers are constrained and controlled by a distributed constrained power control (DCPC) algorithm. Due to transmitter mobility and random signal propagation, there are system states where not all transmitters can be supported, even under the optimal power control. Thus, some of them should be removed. It can be shown that finding the optimal removal set is an NP-complete problem, and therefore gives rise to heuristic algorithms. In this paper we study and compare among three classes of transmitter removal algorithms, one-by-one removals, multiple removals and power control with removals combined. All removal algorithms are compared with respect to their outage probabilities and their time to convergence to a steady state. The power control with removals combined algorithm emerges as the best approach with respect to both criteria.
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| 4. |
- Andersin, Michael, et al.
(författare)
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Soft Admission in Cellular PCS with Constrained Power Control and Noise
- 1995
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Ingår i: Proc 5th WINLAB Workshop on Third Generation Wireless Information Networks. ; , s. 287-320
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Konferensbidrag (refereegranskat)abstract
- We study the mobile admission control problem in a cellular PCS network where trans- mitter powers are constrained and controlled by a Distributed Constrained Power Control (DCPC) algorithm. Receivers are subject to non-negligible noise, and the DCPC attempts to bring each receiver's CIR (Carrier to Interference Ratio) above a given quality target. Two classes of distributed admission controls are considered. One is a Non-Interactive Admission Control (N-IAC), where an admission decision is instantaneously made based on the system state. The other is an Interactive Admission Control (IAC), under which the new mobile is permitted to interact with one or more potential channels before a decision is made. The algorithms are evaluated with respect to their execution time, and their decision errors. Two types of errors are examined. Type I error, where a new mobile is erroneously accepted and results an outage; and type II error, where a new mobile is erroneously rejected and results in blocking. The algorithms in the N-IAC class accept a new mobile, if and only if the uplink and the downlink interferences are below certain corresponding thresholds. These algorithms are subject to errors of type I and type II. In the IAC class, we derive a Soft and Safe (SAS) admission algorithm, which is type I and type II error free, and protects the CIRs of all active links at any moment of time. A Fast-SAS version which is only type I error free, is proposed for practical implementation, and evaluated in several case studies.
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| 5. |
- Badia, Leonardo, et al.
(författare)
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An Economic Model for the Radio Resource Management in Multimedia Wireless Systems
- 2003
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Konferensbidrag (refereegranskat)abstract
- In this paper, we study the connection between Radio Resource Management and economic parameters, whose application in multimedia communication system is a challenging task. In fact, a real network provider has to consider other parameters, besides the common goals of Radio Resource Management like throughput maximisation or meeting constraints connected with the Quality of Service. In particular, when the financial needs of the provider and the reaction of the users to prices are taken into account, economics have to be introduced in the analysis. We intend to study multimedia communication systems by including well-known economic models and reasonable considerations in the usual Radio Resource Allocation scenario. To do this, we present a model of users'satisfaction, which considers the effects of both users' request and price paid. In this way it is possible to investigate the relationship between the Radio Resource Allocation and the provider revenue. Other conclusions can be derived as well, e.g., for the pricing strategy planning or the network dimensioning. Thus, we give analytical insight and numerical results which highlight that the network management is heavily affected by the economic scenario.
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| 6. |
- Badia, Leonardo, et al.
(författare)
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Demand and Pricing Effects on the Radio Resource Allocation of Multimedia Communication Systems
- 2003
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Ingår i: Conference Record / IEEE Global Telecommunications Conference. - : IEEE. ; , s. 4116-4121
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Konferensbidrag (refereegranskat)abstract
- Over the years, Radio Resource Management has been benchmarked mostly by its technical merits. For a service provider, however, also economics must be reckoned with. When the financial needs of the provider and the satisfaction of the users are considered, common objectives in radio resource management like maximising throughput or meeting various quality constraints, may no longer be sufficient. We analyse next generation communication systems by including models of economics, presented in the literature, and reasonable considerations to depict the users/provider relationship in a generalised multimedia environment. In particular, we develop a model of users' satisfaction, in which both requested Quality of Service and price paid are taken into account. The model enables us to investigate how resource allocation dynamics affect operator revenues and to derive some useful insights. The Radio Resource Management can be shown to highly depend on economic considerations. The provider's task to determine the best usage of the network capacity is heavily affected by the users' service demand and their reactions to the pricing policy. Thus, the economic scenario needs to be taken into account to efficiently exploit the constrained radio resource.
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| 7. |
- Berg, Miguel, et al.
(författare)
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A Radio Resource Management Concept for "Bunched" Personal Communication Systems
- 1997
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Konferensbidrag (refereegranskat)abstract
- The radio resource management (RRM) techniques used in current 2nd generation mobile communication systems rely heavily on fixed frequency or timeslot allocation techniques which are not well suited for large variations in data rates. Spread spectrum systems proposed provide partial solutions to this problem but exhibit deficiencies when faced with uneven user populations. The overall objective of ACTS project AC090 FRAMES is to define, develop and evaluate a wideband multiple radio access scheme fulfilling the UMTS requirements. Within the project several RRM concepts have been proposed. The "bunch" concept discussed in this paper uses synchronous dynamic physical layer radio resource reservation combined with fast SIR based power control in a local cluster ("bunch"). Uncontrolled, "inter bunch", interference is handled by time/frequency hopping ("interference averaging"). In the paper some initial performance results are presented.
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| 8. |
- Bria, Aurelian, et al.
(författare)
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Overall design of 4th Generation Wireless Infrastructures (4GW)
- 2002
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Konferensbidrag (refereegranskat)abstract
- An important factor contributing to this uncertainty is that we have very limited knowledge about the future environment in which a fourth generation wireless infrastructure should function. Which of today's systems will still exist when a potential 4G infrastructure is deployed? Which systems and solutions will be considered successful then? What technical bottlenecks will be apparent ten years from now? What market impact will third generation wireless systems have? How will this affect user behavior, and user demands? How much money do prospective users have available to pay for services provided over this infrastructure? This paper presents some of the conclusion of of the Fourth Generation Wireless Infrastructure project (4GW) of the Personal Computing and Communications program (PCC), the major Swedish academic research effort on future communications systems launched in late 1997(1). The vision of the PCC project has been "Personal Multimedia to everyone at today's prices for fixed telephony". In 4GW a scenario-based approach has been used to tackle the issue of identifying reasonable research topics. In the paper we will present this method, and demonstrate how it interfaces with traditional research methods in the fields that the 4GW project incorporates. We will also give an overview of some research results from the project. Finally, we will conclude these results as a vision of what fourth generation wireless infrastructures might become
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| 9. |
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| 10. |
- Englund, Eva, et al.
(författare)
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Tactical Radio Access Networks based on Future Civilian Communication Architectures
- 1999
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Konferensbidrag (refereegranskat)abstract
- We investigate architectures where a tactical radio subsystem can integrate in civilian systems. The idea is that civilian communication infrastructure sould be used whereever it is available. One such possibility may be found in the proposed next generation wireless communication system UMTS, where the defition of a Radio Network Subsystem (RNS), encapsulating all the features of wireless mobile communications has been proposed. We adopt this design paradigm to see if it is possible to find a low cost military network (by maximal use of civilian network technology and communication applications). The idea is to within the framework of an RNS, encapsulate also features specific to tactical wireless communications, a Tactical Radio Access Network (TRAN). Based on UMTS we describe two system concepts and architectures for designing a TRAN. Furthermore, feasibility investigation of the concepts is conducted.
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