1.
Eriksson, T., et al.
(författare)
Successive Encoding of Correlated Sources
1982
Rapport (övrigt vetenskapligt/konstnärligt) abstract
The encoding of a discrete memoryless multiple source for reconstruction of a sequence with is considered. We require that the encoding should be such that is encoded first without any consideration of , while in a seeond part of the encoding this latter sequence is encoded based on knowledge of the outcome of the first encoding. The resulting scheme is called successive encoding. We find general outer and inner bounds for the corresponding set of achievable rates along with a complete single letter characterization for the special case . Comparisons with the Slepian-Wolf problem [3] and the Ahlswede-Körner-Wyner side information problem [2 ], [9) are carried out.
2.
Zander, Jens, et al.
(författare)
SOFTNET – an approach to high level packet communication
1983
Ingår i: Pioneer Papers on Packet Radio 1981-1985, ARRL. - 0872590224 ; , s. 1-2
Konferensbidrag (refereegranskat) abstract
SOFTNET is a packet-radio concept under development in Sweden. The network is distributed and all nodes are programmable via the network during normal operation. This concept represents an unconventional approach to the protocol issue and offers elegant solutions to the higher level communication problems. This paper gives a programming model of the network, along with some illustrating examples.
3.
Zander, Jens
(författare)
Softnet – packet Radio in Sweden
1981
Ingår i: Arrl Amateur Radio: Computer Networking Conferences: Pioneer Papers on Packet Radio 1981-1985. - 0872590224 ; , s. 1-4
Konferensbidrag (refereegranskat) abstract
An experimental packet radio network is under construction at the University of Linkoping, Sweden. The network is distributed and all nodes are programmable via the network during normal operation. This concept gives full flexibility at all levels. Experiments at low levels, such as access schemes, as well as at high levels, such as routing and flow-control, are possible. Finally, the implementation of the network is sketched.
4.
Madala, Hermano
(författare)
Self-Organization GMDH Computer Aided Design for Modelling of Cyclic Processes
1983
Ingår i: Elsevier IFAC Publications / IFAC Proceedings series. - 1474-6670. ; 16:19, s. 611-618
Tidskriftsartikel (refereegranskat) abstract
The Group Method Data Handling (GMDH) is a specific selforganization computer-aided design which has been proposed by Ivakhnenko (1970, 1971) and which has been described in several recent articles (Ivakhnenko et al, 1978, 1979a) and also in Soviet Automatic Control (USA). One of the several interesting properties of this CAD is its apparent ability to make high accuracy predictions of future states of complex systems. The development presents a procedure for constructing models in a simple and systematic way for complex systems which are cyclic in nature. In the present paper the structures of finite-difference models for cyclic processes are described. The criterion of prediction balance is used for analysing the optimal model. System of combined models constructed in this manner is used recursively for predicting the future states of the cyclic system. Three examples are given. One example used the data generated from a known model and the others the airtemperature data with large number of points and the tea-crop production data with less number of points. The system of combined models is compared with the single overall model. The former has given reasonably better results. The models are checked for stability in long-range actions.
5.
6.
7.
Zander, Jens
(författare)
Multiple Access Schemes for Packet Switching in Radio Channels : An Overview
1981
Rapport (övrigt vetenskapligt/konstnärligt) abstract
For almost a century circuit switching has dominated communication / networks. It was not until the beginning of the 70's as switching cost dropped below communication (bandwidth) costs making packet switching networks feasable. For modern computer communications, circuit switching 1s very wasteful, especially over long distances. This is due to the fact that the datastream from computers and terminals is very bursty, with peak to average ratios up to 2000 to | [5]. If, in a circuit switching environment a high bandwidth channel is used to ensure low delay, this channel will be idle most of ~the time. If we instead use a channel with a bandwidth corresponding to the ~average transmission rate, we will get intolerable delays. The above dilemma arises because the users access the channels randomly. We have no way to tell when the channel will be used, so we assign one channel capable of handling peak rates all the time. This is of course wasteful.The packet-switching solution to the situation above is based on the law of large numbers, stating that the sum of all demands from a large number of users will fluctuate very little. around its average. This is usually called statistical load averaging. The implication is clear -we should use a single wideband channel, dynamically shared among the users. This has been utilized in packet-switched computer networks. The datastream is divided into packets. When a packet is ready for transmission, it is allocated some time-slot (possibly after some queuing delay) on the shared channel. The allocation of suitable time-slots is here done by the network facilities.In recent years the use of packet switching in radio channels has been proposed and implemented. 8oth ground radio and satellite channel s have been utilized for packet switching. The radio medium offers several advantages for these applications....
8.
9.
Persson, Iréne E, et al.
(författare)
Design Considerations of a Distributed Packet Radio Network Using the Radio Amateur Band
1980
Rapport (övrigt vetenskapligt/konstnärligt) abstract
The paper outlines an experimental radio based data network to be used by radio amateurs and computer hobbyists. Various aspects of network design is discussed with the intention to provide a foundation on which a more detailed specification can be based. Underlaying principles and qualitative rather than quantitative results are stressed.
10.
Ericson, Thomas
(författare)
A Converse to the Sampling Theorem
1982
Rapport (övrigt vetenskapligt/konstnärligt) abstract
Various forms of the sampling theorem assure that any signal x(t) which satisfies a certain bandwidth limitation can be uniquely reconstructed from its values at equally spaced sample points. Inherent in all these results is that the reconstruction is invariant under timeshifts. Our present result is that if such a time shift invariance is required, a certain bandwidth limitation is not only a sufficient but also a necessary condition for reconstruction of a signal from its sample values.
