Showing papers on "Channel allocation schemes published in 1992"
TL;DR: In order to derive upper performance bounds for transmitter power control schemes, algorithms that are optimum in the sense that the interference probability is minimized are suggested.
Abstract: Most cellular radio systems provide for the use of transmitter power control to reduce cochannel interference for a given channel allocation. Efficient interference management aims at achieving acceptable carrier-to-interference ratios in all active communication links in the system. Such schemes for the control of cochannel interference are investigated. The effect of adjacent channel interference is neglected. As a performance measure, the interference (outage) probability is used, i.e., the probability that a randomly chosen link is subject to excessive interference. In order to derive upper performance bounds for transmitter power control schemes, algorithms that are optimum in the sense that the interference probability is minimized are suggested. Numerical results indicate that these upper bounds exceed the performance of conventional systems by an order of magnitude regarding interference suppression and by a factor of 3 to 4 regarding the system capacity. The structure of the optimum algorithm shows that efficient power control and dynamic channel assignment algorithms are closely related. >
1,256 citations
Patent•
14 Dec 1992TL;DR: In this article, a base station (21, 22, 23) comprises a channel allocator (62) for allocating communication channels by accessing a Preferred Channel List (PCL) (64), which ranks channels (116) in accordance with the occurrence of prior events on the channels (112), such as interrupted calls, blocked call setup requests, and calls successfully completed (106), and in regards to the mean quality margin (110) and the current channel quality (114).
Abstract: A base station (21, 22, 23) in a radio communication system (20) comprises a channel allocator (62) for allocating communication channels by accessing a Preferred Channel List (PCL) (64). The PCL ranks channels (116) in accordance with the occurrence of prior events on the channels (112), such as interrupted calls (122), blocked call setup requests (118), and calls successfully completed (106) and in regards to the mean quality margin (110) and the current channel quality (114). The channel allocator (62) allocates (140) the first available channel (128) in the PCL having a free timeslot (132) and with good current channel quality (136).
164 citations
NEC1
TL;DR: A simple, decentralized procedure for adaptive channel allocation, autonomous reuse partitioning (ARP), is proposed, which doubles traffic handling capacity and decreases the probability of interference by 1/4 and improves traffic handlingcapacity at the cost of CIR margin in each channel.
Abstract: A simple, decentralized procedure for adaptive channel allocation, autonomous reuse partitioning (ARP), is proposed. Radio channels are viewed in the same order at any base station, and the first channel that satisfies a carrier-to-interference ratio (CIR) threshold is allocated. ARP easily achieves reuse partitioning, in which channels higher in the order are reused at shorter distance by mobile stations from which stronger signal levels are received. An efficient frequency reuse pattern helps ARP to improve traffic handling capacity while avoiding interference. Performance was evaluated by means of computer simulation in which a system accommodating portable units with 70 channels is assumed. Compared with random channel allocation, ARP doubles traffic handling capacity and decreases the probability of interference by 1/4. Actual transmitter power control is shown to improve capacity by 9%. ARP improves traffic handling capacity at the cost of CIR margin in each channel. This can create problems for mobile stations, such as car-mounted units, which suffer rapid fluctuation in signal levels. >
109 citations
Patent•
18 Nov 1992
TL;DR: In this paper, the authors propose a dynamic channel allocation in an ISDN line over a Level II link layer protocol (LAPD) that includes a channel management module (CMM) and a virtual channel module (VCM) to implement dynamic channel Allocation.
Abstract: Dynamic channel allocation in an ISDN line is implemented above a Level II link layer protocol (LAPD). The preferred embodiment comprises programming operating on a computing platform system including a communication coprocessor system. The programming includes a channel management module (CMM) and a virtual channel module (VCM) to implement dynamic channel Allocation. The modules cooperate to control bandwidth between communication partners by selective allocation and deallocation of virtual B-Channels between them in response to preassigned priorities and real time events. Voice and data channels are interrogated. Channel deallocation also takes place in response to high error rates in message transmission.
108 citations
10 May 1992
TL;DR: The capacity of a microcellular system using dynamic channel allocation was studied and it was found that these systems can self-organize, with little loss in capacity, by using channel-allocation algorithms that are simple, practical, and local.
Abstract: The capacity of a microcellular system using dynamic channel allocation was studied. It was found that these systems can self-organize, with little loss in capacity, by using channel-allocation algorithms that are simple, practical, and local. The performances of both deterministic and probabilistic algorithms were calculated. Two classes of isotropic algorithms look particularly promising: the timid class, which is the simplest, and the aggressive class, which could provide improvements in system capacity and blocking probability. In particular, at the expense of additional rearrangements per call, these local algorithms can approach the capacity achieved by a global channel-allocation strategy. >
63 citations
14 Jun 1992
TL;DR: The authors determine the blocking performance of channel allocation algorithms where every channel is available for use in every cell and where decisions are made by mobiles based only on local observations and suggest that an aggressive algorithm could provide substantially reduced blocking.
Abstract: The authors determine the blocking performance of channel allocation algorithms where every channel is available for use in every cell and where decisions are made by mobiles based only on local observations. Using a novel Erlang-B approximation method, together with simulation, they demonstrate that even the simplest algorithm, the timid, compares favorably with impractical, centrally administered fixed channel allocation. The results suggest that an aggressive algorithm, that is, one requiring call reconfigurations, could provide substantially reduced blocking. Practical algorithms are presented that take major steps toward achieving the excellent performance of the best aggressive algorithm but that have the stability of the timid algorithm. >
47 citations
Patent•
21 Apr 1992
TL;DR: In this paper, a method and apparatus for operating a frequency division multiplexing (FDM) transmitter within a common communication channel is disclosed, where the system randomly allocates each separate channel within the available bandwidth to provide an initial set of separate channel allocation and corresponding carrier frequencies.
Abstract: A method and apparatus for operating a frequency division multiplexing (FDM) transmitter within a common communication channel is disclosed. The carrier frequency for each separate channel is adjusted for minimizing intermodulation interference. The system randomly allocates each separate channel within the available bandwidth to provide an initial set of separate channel allocation and corresponding carrier frequencies. Thereafter carrier to intermodulation ratio (C/IM) on each channel is measured and the worst channel with the lowest carrier to intermodulation ratio (C/IM) is removed. The system then repeatedly inserts a channel in available unoccupied bandwidth to produce the largest minimum carrier to intermodulation ratio (C/IM). The deletion and insertion continues until no improvement in minimum carrier to intermodulation ratio (C/IM) can be achieved for said random allocation of separate channels. The selected set of separate channel allocations is further fine-tuned by deleting the worst channel with minimum carrier to intermodulation ratio (C/IM) and deleting one other channel from said separate channel allocations to provide a particular dual channel deletion. The system then repeatedly inserts two channels in available unoccupied bandwidth which produces the largest minimum carrier to intermodulation ratio (C/IM). The system continues on dual deletion and insertion until no improvement in minimum carrier to intermodulation ratio (C/IM) can be achieved for said random allocation of separate channels. The carrier frequencies are then tuned according to said set of separate channel allocation.
39 citations
10 May 1992
TL;DR: Results from simulations of an adaptive channel allocation algorithm which can be implemented in a microcellular system conforming to the TIA standard IS-54 are presented and show that the tested algorithm would perform well and also give an increase in capacity in comparison to a fixed channel allocation (FCA).
Abstract: Results from simulations of an adaptive channel allocation (ACA) algorithm which can be implemented in a microcellular system conforming to the TIA standard IS-54 are presented. The algorithm is completely decentralized, i.e., the allocation of a channel can be done at the base without any explicit reference to other bases. The results of the simulations show that the tested algorithm would perform well and also give an increase in capacity in comparison to a fixed channel allocation (FCA). >
29 citations
Patent•
11 Aug 1992
TL;DR: In this article, an exchange is connected to a general telephone network, an exchange 61 for connecting lines in general telephone networks is connected with plural line control stations 62 for controlling plural base stations 63 and each base station 63 executes communication with each mobile station 64 existing in an optional radio zone 65 through a radio transmission line.
Abstract: PURPOSE:To suppress the increment of measuring frequency for a required wave to an interference wave level at the time of allocating a channel by dividing all communication channels and applying an ARP system and a channel occupation system to the divided channels. CONSTITUTION:In this mobile communication system, an exchange 61 for connecting lines in a general telephone network is connected to plural line control stations 62 for controlling plural base stations 63 and each base station 63 executes communication with each mobile station 64 existing in an optional radio zone 65 through a radio transmission line. When the total number of communication channels is set up to N, communication channels in a 1st channel group are 1 to M and communication channels in a 2nd channel group are (M+1) to N, the priority order of respective channels 1 to M is set up to the same level and the ARP system is applied to the channels 1 to M. Each base station monitors channel allocation requests and the occupation of channel arrangement is learned in each base station 63 so that the priority of a certain channel in the channels (M+1) to N is increased when its interference wave level is less than a prescribed level or reduced when more than the prescribed level.
24 citations
02 Jan 1992
TL;DR: This paper presents an Overview of Code Division Multiple Access Applied to the Design of Personal Communications Networks, and a Multiple Access Technique for Radio-Local Area Networks.
Abstract: 1. Developments in Wireless Communications - Navigating the Regulatory Morass.- 2. Why do We Need Standards for Mobile/Wireless Communications.- 3. Standards for Global Personal Communications Services.- 4. WIN with OSI.- 5. Trellis Coding for Full-Response CPM.- 6. Design Considerations for a Future Portable Multimedia Terminal.- 7. Dynamic Resource Acquisition: Distributed Carrier Allocation for Tdma Cellular Systems.- 8. On Dynamic Channel Allocation in Cellular/Wireless Networks.- 9. A Radio-Local Area Network with Efficient Resource Allocation.- 10. Radio Channel Control for a Multi-Carrier TDMA Microcell System.- 11. Models for Call Hand-Off Schemes in Cellular Communication Networks.- 12. Handoff in Microcellular Based Personal Telephone Systems.- 13. Sip Simulation for Urban Microcells.- 14. Evaluation of VTS CSMA for Media Access Control in Land Mobile Data Communication.- 15. Analytical Performance Evaluation of the R-BTMA Mac Protocol.- 16. A Multiple Access Technique for Radio-Local Area Networks.- 17. Spread Spectrum Wireless Information Networks for the Small Office.- 18. An Overview of Code Division Multiple Access (CDMA) Applied to the Design of Personal Communications Networks.- 19. CDMA Power Control for Wireless Networks.
22 citations
02 Jan 1992
TL;DR: When using small microcells with antennas mounted at lamp post level the propagation characteristics will be very different from traditional large cells, so very fast handoff algorithms and, maybe, new strategies will be required.
Abstract: When using small microcells with antennas mounted at lamp post level the propagation characteristics will be very different from traditional large cells. Firstly, the so called street corner effect, i.e. 20–30 dB drop of signal level in 10–20 m, have to be considered. Very fast handoff algorithms and, maybe, new strategies will be required. Furthermore the number of handoffs per call will increase, due to the small cell size. Each handoff must therefore be made with high success rate. Secondly, the propagation is very difficult to predict since it depends to a large extent on the local environment. This makes it very difficult to find a fixed reuse plan, i.e. dynamic channel allocation (DCA) is probably required. In this paper we concentrate on the handoff issue. Some discussion on the propagation characteristics and DCA is however also made.
01 May 1992
TL;DR: The authors introduce a control strategy for bandwidth management in asynchronous transfer mode (ATM) networks where one level performs fixed class-selective call admission control strategies that are periodically dynamically coordinated by a higher-level bandwidth allocation controller.
Abstract: The authors introduce a control strategy for bandwidth management in asynchronous transfer mode (ATM) networks. A two-level hierarchy is defined, where one level performs fixed class-selective call admission control strategies that are periodically dynamically coordinated by a higher-level bandwidth allocation controller. Each admission controller decides to accept or refuse an incoming call on the basis of a class-selective rule designed to maintain a certain quality of service. A decision is taken according to the virtual capacity share that is assigned to the various service classes by the allocation controller. Bandwidth shares are periodically recomputed online by means of the constrained minimization of a cost function that takes cell loss probability and refused traffic into account. The control structure, the strategies, and the optimization algorithm used are described as well as the assumptions underlying the choices made. Initial simulation results are reported. >
10 May 1992
TL;DR: In this article, two control techniques are proposed for assigning radio channels in order to increase the spectrum efficiency, one is an autonomous channel assignment control for reusing radio channels at shorter distances according to the conditions of channels, and the other is a control for assigning the channel of a neighboring cell when there is no available channel in the closest cell.
Abstract: Two control techniques are proposed for assigning radio channels in order to increase the spectrum efficiency. One is an autonomous channel assignment control for reusing radio channels at shorter distances according to the conditions of channels. The other is a control for assigning the channel of a neighboring cell when there is no available channel in the closest cell. It is shown that these techniques are significant in mobile radio systems using sector cells and TDMA channels, and the spectrum efficiency is clarified by comparison of system capacity. >
06 Dec 1992
TL;DR: Two techniques that facilitate the transmission of linear time-division multiaccess (TDMA) signals from a mobile radio base station are proposed and the Cartesian loop technique is applied in a first-order loop configuration and shown to exhibit an excellent transient response when driven with a rapidly switched TDMA waveform.
Abstract: Two techniques that facilitate the transmission of linear time-division multiaccess (TDMA) signals from a mobile radio base station are proposed. The Cartesian loop technique is applied in a first-order loop configuration and shown to exhibit an excellent transient response when driven with a rapidly switched TDMA waveform. The practical implementation of a feedforward technique is also discussed and shown to be applicable to multicarrier systems employing dynamic channel allocation. Practical results are presented for both systems. >
29 Sep 1992
TL;DR: In this paper, the authors introduce a new type of 1-0 array and show how they are used in maximizing the line-of-sight and non-line-ofsight distance between co-channel cells.
Abstract: The demand for cellular service will increase dramatically in the near future One way of increasing the cellular system capacity is by reducing the cell size The authors discuss the problems associated with the new microcell environment The propagation characteristics of the system are discussed and various types of microcell coverages introduced In order to solve the cell planning problem, the authors introduce a new type of 1-0 array and show how they are used in maximizing the line-of-sight and nonline-of-sight distance between co-channel cells The properties of the 1-0 array are established and examples of cell planing for various reuse distances are given >
Patent•
27 Jun 1992
TL;DR: In this paper, the authors proposed a method based on a digital terrain database which contains the land utilisation values required for the calculation of the coverage areas of the transmitters, which is used for the efficient planning of radio communication systems and the optimum adaptation of existing radio networks to current requirements and changed conditions.
Abstract: 2.1 The method according to the invention is intended to enable computer-aided planning of cellular radio networks, data for effective channel allocation being intended to be derivable taking into account the values required in relation to the coverage areas. 2.2 The method according to the invention is based on a digital terrain database which contains the land utilisation values required for the calculation. The coverage areas of the transmitters are underlaid on graphics monitors with digitised topographical maps. The superimposition of the individual coverage areas and the conversion of the field-strength forecast in the event of variation of the radio-specific parameters of transmitting stations and their interference characteristics are interactively analysed. The data obtained from the interference analysis, together with the required values relating to coverage areas which are retrieved from the traffic database, form the input parameters for the channel allocation. 2.3 The method according to the invention is used for the efficient planning of radio communication systems and the optimum adaptation of existing radio networks to current requirements and changed conditions.
10 May 1992
TL;DR: In this paper, a more realistic and general simulation showed the improvements, in terms of quality parameters and capacity, obtained with the proposed DCA algorithm, and some comments derived from software simulations in very simple situations, are made.
Abstract: The introduction of dynamic channel allocation (DCA) schemes in future microcellular systems needs proper evaluation of their stability behavior. Some parameters are suggested for simplified analysis, and some comments, derived from software simulations in very simple situations, are made. A more realistic and general simulation showed the improvements, in terms of quality parameters and capacity, obtained with the proposed DCA algorithm. This should not be considered an optimal system, but just an indication of a good direction. >
10 May 1992
TL;DR: A simple dynamic channel allocation algorithm for one-dimensional cellular systems is proposed and is shown to maximize the number of assigned calls and lends itself to distributed implementation.
Abstract: In existing macrocellular systems, microcells may be used to increase the capacity in areas with large traffic demands. Examples of such areas are roads and streets where the microcells will form one-dimensional structures. Using smaller cells implies that the variations in telephone traffic load will increase. To adapt to these variations, a simple dynamic channel allocation algorithm for one-dimensional cellular systems is proposed. The algorithm is shown to maximize the number of assigned calls and lends itself to distributed implementation. >
Patent•
27 Jan 1992
TL;DR: In this article, the authors proposed to reduce the number of the sensing times of a carrier and improve reliability by giving the notice of the use situation of a radio channel between base stations in an interference area and permitting respective base stations to individually judge whether the radio channel can be used or not.
Abstract: PURPOSE: To reduce the number of the sensing times of a carrier and to improve reliability by giving the notice of the use situation of a radio channel between base stations in an interference area and permitting respective base stations to individually judge whether the radio channel can be used or not. CONSTITUTION: Respective interference stations BS1-BS6 give the notice of information of the radio channel which is used in the own station at a prescribed period or whenever a change occurs to the base station BS0 by links r1-r6 by the radio channels from the interference stations BS1-BS8 to the base station BS0. The base station BS0 generates a channel use situation table for judging the channel which can be used and the channel which cannot be used in the own station by the radio channel which is used in the own station and channel use information from the interference stations. Then, the allocation processing of the radio channel is executed based on the table. Thus, it becomes unnecessary to sense the carrier whenever the channel allocation processing is executed, and the processing is made efficient. COPYRIGHT: (C)1993,JPO&Japio
29 Sep 1992
TL;DR: In this article, channel segregation (SEG) has been proposed as a sophisticated dynamic channel assignment (DCA) method for TDMA/FDMA microcellular systems, where the base station does not load with full system channels as seen in a conventional cellular system.
Abstract: Spectrum efficiency for a TDMA/FDMA microcellular system, where the base station does not load with full system channels as is seen in a conventional cellular system, can be heavily deteriorated if a coordinated use of the channels is not adopted: the random use of the channels on the same frequency between neighboring cells is most harmful. The authors show that the channel segregation (SEG) which has been proposed as a sophisticated dynamic channel assignment (DCA) method, has a capability to resolve this problem. Results of the analysis with computer simulation reveal that the SEG gives a higher spectrum efficiency compared with the conventional DCA, when applied to a TDMA/FDMA microcellular system. No significant modification to the SEG algorithm is required except that the channel usage is restricted depending on the channel usage situation due to the partial loading of the channels. >
06 Dec 1992
TL;DR: The extensive results show that the investigated policy can provide significant connection-cost savings and is shown how cross-connection costs can be optimized if steady-state user behavior is assumed.
Abstract: A two-level bandwidth negotiation algorithm used in fiber distributed data interface (FDDI) bridges to obtain a dynamically adaptive bandwidth in the wide area backbone is analyzed and optimized. On the basis of a set of reasonable assumptions on the features of asynchronous transfer mode (ATM) networks, it is shown how cross-connection costs can be optimized if steady-state user behavior is assumed. The extensive results show that the investigated policy can provide significant connection-cost savings. The results are obtained by numerically solving an analytical model, which has also been validated by simulation. >
01 Jan 1992
TL;DR: This dissertation considers queuing models that capture the above characteristics of radio networks and discusses throughput, delay performance and optimal dynamic control problems in these systems and methods of stochastic stability theory are employed.
Abstract: Wireless communication networks exhibit fundamental differences from networks with dedicated point-to-point connections. Channel access and packet routing problems are closely related in radio networks, therefore should be considered jointly. Changing connectivity arises naturally in wireless systems in several cases (i.e. mobile radio nodes, meteor-burst channels) and should be taken into consideration by the channel access protocols. In this dissertation we consider queuing models that capture the above characteristics of radio networks and discuss throughput, delay performance and optimal dynamic control problems in these systems. Channel access and packet routing are studied jointly in a queuing system with interdependent servers that models a multihop radio network with scheduled link activation. Dynamic scheduling schemes are investigated. The performance of a scheduling policy $\pi$ is characterized by its stability region that is the set of arrival rates for which the network is stable under $\pi$. We obtain a scheduling policy which is optimal in the sense that its stability region dominates the stability region of every other policy and we characterize that region. Methods of stochastic stability theory are employed in this study. In addition to system stability, the issue of queuing delay is of particular importance in communication networks. For a tandem radio network we obtain link activation scheduling policies which are optimal with respect to delay in the stochastic ordering sense; the result in this case is obtained using sample path comparison arguments. Turning to the issue of changing connectivity, a single hop radio network is considered where the user connectivity is modeled by a stochastic process. The necessary and sufficient stabilizability condition as well as a stabilizing policy are obtained. In the case of a symmetric system with unlimited buffer capacity at each user, the channel allocation policy that minimizes the delay is obtained. When each user possesses a single buffer the channel allocation policy that minimizes both throughput and delay is specified. Finally stability issues are investigated in a general queuing network where there is routing and flow control at each queue. The implications of the stability results on deterministic flow networks are discussed.
02 Jan 1992
TL;DR: This paper studies several dynamic channel allocation methods, including channel borrowing and hybrid techniques, and analyzes them in a stochastic framework, and facilitates a finer comparison than the conventional approaches.
Abstract: With the trend towards higher network performance in cellular and wireless networks, traffic sensitive methods that assign available channels to cells (macro and micro) more dynamically (instead of fixed assignment) may prove beneficial In general, dynamic channel allocation methods can generate better capacity and better handoff performance (lesser forced terminations) Previous studies of dynamic methods are largely simulation based, and theoretical studies aimed at a better understanding of the benefits are relatively few In this paper, we study several dynamic channel allocation methods, including channel borrowing and hybrid techniques, and analyze them in a stochastic framework Comparison of allocation methods using stochastic dominance concept is illustrated This facilitates a finer comparison than the conventional approaches Bounds indicating the conditions under which dynamic methods considered dominate fixed allocation methods are also developed Simulation studies are also reported
10 May 1992
TL;DR: In this paper, the authors considered the effect of a varying carrier-to-interference ratio on channel efficiency and showed that there is a point of diminishing returns beyond which the advantage of higher channel efficiency is outweighed by reduced frequency reuse.
Abstract: The formula for cellular radio capacity is modified to explicitly include channel efficiency. The effect of a varying carrier-to-interference ratio is considered. Higher carrier power can lead to higher bit-rates per hertz of bandwidth for individual channels, but it reduces the frequency reuse. The tradeoff between these two effects is made explicit. It is seen that there is a point of diminishing returns beyond which the advantage of higher channel efficiency is outweighed by reduced frequency reuse. There should be an optimum carrier-to-interference ratio that maximizes the capacity as measured in number of channels per cell. >
13 Sep 1992
TL;DR: It turns out that the guaranteed bandwidth protocol is an excellent candidate for connection oriented data service in DQDB where support of delay-sensitive VBR traffic is a major concern.
Abstract: Two strategies which have recently been proposed for bandwidth allocation in distributed-queue dual-bus (DQDB) subnetworks of a metropolitan area network (MAN) are compared. Studied are packet delays for connection oriented variable-bit-rate (VBR) traffic such as real-time data and compressed voice and video. It turns out that the guaranteed bandwidth protocol is an excellent candidate for connection oriented data service in DQDB where support of delay-sensitive VBR traffic is a major concern. In contrast to this, a modified version of the bandwidth balancing mechanism suffers from slow convergence to the desired bandwidth allocation. >
TL;DR: The authors discuss the performance analyses of a novel demand assignment multiple access (DAMA) scheme addressing the special characteristics of the mobile radio service (MRS), and a new method for dynamically allocating a common pool of channels to both MRS and mobile telephone service ( MTS) to improve channel utilization.
Abstract: The authors discuss the performance analyses of a novel demand assignment multiple access (DAMA) scheme addressing the special characteristics of the mobile radio service (MRS), and a new method for dynamically allocating a common pool of channels to both MRS and mobile telephone service (MTS) to improve channel utilization. The new DAMA scheme makes use of call queuing, batch processing, and pipelined signaling to minimize call setup overhead for MRS traffic. MRS call setup delays were analyzed by simulation modeling of a mobile satellite system (MSS) with many mobile voice-dispatch networks operating over a multiple spot beam satellite to investigate the effects of traffic volume, batch size, and batch service disciplines. A reserved channel margin algorithm for dynamic channel allocation was shown to be effective in harmonizing the different call setup performance requirements for MTS and MRS. Numerical results show that dynamic channel allocation applied to a common pool of 40 channels enables a 20-25% increase in the number of mobile terminals compared with a fixed allocation of 20 channels to each of the two services. >
29 Sep 1992
TL;DR: The author studies the characteristics of two leading candidates for the radio channel assignment method in personal communications services (PCS) systems: the quasi-static autonomous frequency assignment (QSAFA) method and the dynamic channel allocation (DCA) method.
Abstract: The author studies the characteristics of two leading candidates for the radio channel assignment method in personal communications services (PCS) systems: the quasi-static autonomous frequency assignment (QSAFA) method and the dynamic channel allocation (DCA) method The author first describes channel planning, the QSAFA method, and the DCA method The author then discusses the characteristics of these two methods in terms of link setup and automatic link transfer, synchronization requirement, implementation complexity for multiple service providers, spectrum efficiency and signal quality, and other relevant issues >
TL;DR: With DRAMA, the advantage off CSMA/CD is extended from low load and medium speed (10 Mbps to high load and high speed networks (> 100 Mbps) and these properties are demonstrated through simulation studies.
Abstract: Techniques are presented that integrate synchronous traffic (real time voice or video) and asynchronous traffic (e.g., file transfers, mail messages) and extend the size of local area networks to distances much greater than 2 km without loss in speed and capacity. The system, Dynamic Resource Allocation in Metropolitan Areas (DRAMA), is based on broadband technology and allows for allocation of bandwidth among clusters of nodes in the total network. DRAMA incorporates both channel allocation and traffic placement protocols. Its channel allocation algorithm is shown to be fair, stable and responsive to dynamic load conditions and reallocates resources in a near optimal manner. The suggested traffic placement protocol is based upon CSMA/CD access; it provides effective integration of synchronous and asynchronous traffic, handles diverse loads and momentary traffic overloads, varying numbers of nodes and modifications to the network structure. With DRAMA, we have extended the advantage off CSMA/CD from low load and medium speed (10 Mbps to high load and high speed networks (> 100 Mbps). These properties are demonstrated through simulation studies.
10 May 1992
TL;DR: The results show that models of channel activity can be learned and that controllers can learn to use these models to allocate channels and that such controllers perform better than a fixed controller that does not learn.
Abstract: Preliminary investigations into using connectionist machine learning for dynamic channel allocation in real time are described. The algorithms were implemented on a simple radio testbed. It consists of a channel allocator and two channel requesters. The channel allocator is a computer that communicates via a transceiver. It learns to model the time-dependent behavior of the two channel requesters, and thereby learns to allocate channels dynamically. Channels are requested by two different transceivers run by small processors. The learning criterion is to minimize a cost function of channel use. The results show that models of channel activity can be learned and that controllers can learn to use these models to allocate channels. A comparison indicates that such controllers perform better than a fixed controller that does not learn. >
Patent•
30 Jan 1992
TL;DR: In this paper, the authors proposed an optimal channel allocation system for the allocation of a channel by deriving the area multiplicity, based on a signal level and the receiving frequency of control information of every channel.
Abstract: PURPOSE:To realize the appreciate arrangement and allocation of a channel by deriving the area multiplicity, based on a signal level and the receiving frequency of control information of every channel, receiving the control information of an adjacent radio base station, and comparing its quality CONSTITUTION:According to this optimal channel allocating system, plural radio base stations 6A, 6B and 6C are connected mutually through a wire network 1, and the base stations 6A, 6B and 6C contain an arbitrary terminal 7 in plural radio terminals 7 In the case each base station 6A, 6B and 6C selects and allocates one channel in plural allocatable channels to the terminal 7 contained in itself, it receives all receivable control information transmitted from other radio base station in advance, and derives area multiplicity which becomes an index of easiness of generation of a communication disturbance whose elements are signal level and the receiving frequency of control information of every channel Subsequently, by selecting in order from the lowest area multiplicity concerned, the channel allocation is executed In such a way, an appropriate channel arrangement can be executed