We consider a scenario where N users try to access a common base station. Associated with each user is its channel state and a finite queue which varies with time. Each user chooses his power and the admission control variable in a dynamic manner so as to maximize his expected throughput. The throughput of each user is a function of the actions and states of all users. The scenario considers th...

We present an analysis of delay encountered in successfully accessing the Random Access Channel (RACH) of Universal Mobile Telecommunication System (UMTS) Radio Interface by User Equipments (UE) that want to initiate data transfer. The process of random channel access is described and the MS state modeled as a DTMC in order to derive the delay. We evaluate the variation of the channel access de...

During the development, testing, and use of System/360, difficulties and problems were logged, but few received the attention given to the Direct Access Storage Device (DASD). This was not necessarily because DASD attachment and use had greater inefficiencies or design problems than other devices. With System/360, DASD attained a prominence it never had before, since no previous system was as ...

Abstract—The diagonalization of a conventional multiple-input multiple-output (MIMO) channel into parallel and independent subchannels via singular value decomposition (SVD) is a fundamental strategy that allows the MIMO channel capacity to be achieved using scalar channel codes. This letter establishes a similar channel diagonalization result for the uplink and the downlink of a cloud radio ac...

The physical layer security in the up-link of the wireless communication systems is often modeled as the multiple access wiretap channel (MAC-WT), and recently it has received a lot attention. In this paper, the MAC-WT has been re-visited by considering the situation that the legitimate receiver feeds his received channel output back to the transmitters via two noiseless channels, respectively....

We consider the task of opportunistic channel access in a primary system composed of independent Gilbert-Elliot channels where the secondary (or opportunistic) user does not dispose of a priori information regarding the statistical characteristics of the system. It is shown that this problem may be cast into the framework of model-based learning in a specific class of Partially Observed Markov ...

Multiple access control (MAC) of the uplink in a wireless mobile computing system is one of the most important resource allocation problems in that the response time and throughput of user applications (e.g., wireless Web surfing) are critically affected by the efficiency of the MAC protocol. Compared with a traditional MAC problem (e.g., the wireline Ethernet), there are two important new chal...

SUMMARY A T user multiple access collision channel without feedback is considered where the channel inputs are called packets. The packets take values from non-binary input alphabet. It is supposed that at most M users are active, i.e., are communicating simultaneously (2 ≤ M T). We are looking for codes and protocol sequences of users of minimum length such that from the output of the channel ...

Multiple-user information theory, or network information theory, was started by C. E. Shannon, the founder of Information Theory [1]. The only multiple-user channel in classical information theory whose single-letter capacity region is completely known, is the multiple access channel (MAC). MAC is a channel with a single output and two (or more) inputs. Its capacity region was determined by R. ...

In this course so far, we have studied two kinds of links that connect computers together: a point-to-point link, typically constructed from a wire, and a shared medium such as radio, for which we developed frequency division multiplexing. In a point-to-point link, the sharing of the link can be done by the switch to which the link is connected. In contrast, when using a shared medium to connec...