The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This study concerns about Beamforming techniques in a Multi-User Indoor environment at mm-Wave E-band. Directional mm-Wave measurement data are used as reliable radio channel reference for the study and, furthermore, are checked against advanced Ray Tracing simulations. The main goal is to assess the quality of Spatial Division Multiple Access using three different Beamforming schemes in order to...
The authors propose a new tool to extensively analyze and plan the radio resources based on machine learning technique using available data analytics methods like clustering, correlation and regression. This will be done through; Classifying the cells according to their Priority and required quality of service, detecting resources utilization that cause throughput limitation, efficient dimensioning...
In this paper we study how to estimate the back-off rates in an idealized CSMA network consisting of n links to achieve a given throughput vector using free energy approximations. More specifically, we introduce the class of region-based free energy approximations with clique belief and present a closed form expression for the back-off rates based on the zero gradient points of the free energy approximation...
Scientific HPC applications along with the emerging class of Big Data and Machine Learning workloads are rapidly driving the fabric scale both on premises and in the cloud. Achieving high aggregate fabric throughput is paramount to the overall performance of the application. However, achieving high fabric throughput at scale can be challenging - that is, the application communication pattern will...
Channel access procedures of the state-of-the-art cellular standards create a significant overhead for small messages transmitted by Internet of Things (IoT) devices. As IoT becomes a major source of traffic for next-generation wireless communications, there are recent efforts to design low-overhead access schemes. Here we present the delay and capacity analysis of two low-overhead access protocols...
The number of small wireless devices is rapidly increasing, making the radio channel efficiency in limited geographic areas (individual rooms or buildings) an important metric for MAC protocols. Many of these emerging devices have use-cases that are difficult to satisfy with current hardware solutions and channel access methods; for instance device mobility, small energy reserves, and requirements...
The high densities of network nodes has made spatial reuse an essential characteristic of modern wireless networks. In this paper, we evaluate the maximum throughput of Carrier Sense Multiple Access (CSMA) for Vehicular Ad-hoc Networks (VANETs) when spatial reuse is taken into account. We begin our study by extending a simple stochastic model in order to fit a VANET pattern and to obtain the spatial...
In this paper, we propose a novel architecture for IDMA system with low latency and high throughput for the uplink multi-user wireless system. The throughput of the proposed IDMA system can be improved to about double compared to the conventional IDMA system while the hardware complexity remains unchanged. To achieve this, the proposed system utilizes the interleaver/de-interleaver-less architecture...
By offloading mobile traffic for macrocells, small cells can help to alleviate the pressure on conventional cellular networks from explosive data growth. On the other hand, the severe spectrum scarcity problem has prompted the research on spectrum sharing recently. In this paper, a spectrum sharing system of OFDMA small cells overlaying CDMA networks is considered, in which each OFDMA user in the...
The growth of customers in 3G network has forced the operators to always optimize their network performances. One of the most concerned parameters to indicate the quality of network is the interference area. Especially in 3G network, this parameter is directly influenced by the number of users. Hence, it would be better if the operators can predict the areas experiencing interference before getting...
In this paper, we propose a new IP transmission architecture over optical fast frequency hopping code-division multiple-access (OFFH-CDMA) network capable of supporting multirate transmissions for applications in flexible optical access networks. The proposed network architecture is independent of the spreading code employed and does not require any new optical processing technology. The performance...
Electromagnetic spectrum is a scarce resource. Spectrum licensing is estimated to consume about 20% of cellular operators' capital expenditure (CAPEX). One important measure of spectrum use is “spectral efficiency” (SE), which is the amount of data bandwidth that a specific technology can extract from a certain amount of radio spectrum and is measured in bits per second per Hz (bps/Hz). Using data...
Licensed-assisted access (LAA), which conveys control signal via licensed anchor carrier and data information via both licensed and unlicensed bands, is a promising solution to enhance the throughput of wireless communications. In view of the potential impact on the incumbent services in the unlicensed band, how to design the medium access control (MAC) protocol for LAA system to make fair and friendly...
Spatial throughput (i.e. throughput with spatial reuse) is important with new types of networks such as vehicular, sensor and military networks. The aim of this study is to compute the spatial throughput of Aloha and CSMA using tools for stochastic geometry. Our network nodes will be modeled as elements of a Poisson Point Process (PPP) of a one- or two-dimensional space. Spatial Aloha can be modeled...
This paper deals with the performance analysis of three different medium access techniques, namely contention-based, scheduled and polling-based access, utilized in a simple implementation of the wireless body area network (WBAN) IEEE 802.15.6 standard. Their comparison is focused on the trade-offs between polling and scheduled access, in terms of throughput, latency and energy consumption, and reveals...
In the world of telecommunication, demand for 3G mobile communication services still dominates the global market. It continues to grow despite the introduction of new technologies such as LTE and LTE-A. Hybrid Automatic Repeat Request (HARQ) and Adaptive modulation and coding (AMC) are among the key performance enhancing techniques adopted in High Speed downlink packet access (HSDPA). Limiting the...
As new congestion control mechanisms are developed, their performance relative to existing mechanisms needs to be understood, in particular over wireless networks. This study aimed to evaluate existing TCP congestion control mechanisms using a comprehensive and reproducible methodology designed to be representative of real world usage of wireless networks. The study sought to investigate whether any...
Satellite Mobile Radio Talk-group (SMRT) multi-group service is envisaged to operate in geo-stationary orbit and serve to facilitate communication among terminal users, under emergency situations. The terminal users are assigned in groups at the time of registration and the channel allocation is done on the basis of the groups. SMRT multi-group service makes use of two types of channels: signaling...
In this paper, the spread-spectrum binary countdown scheme with generalized modified prime sequence codes (GMPSC) is considered as the MAC protocol in the multi-hop network. We focus on the code division multiple access (CDMA) based relay network using binary countdown scheme with GMPSC. The packet success rate and the throughput of binary countdown scheme with GMPSC are evaluated by taking into account...
Traditional algorithms for Media Access Control (MAC) in Mobile Ad Hoc Networks (MANET) such as CSMA-CA allow only a single user to transmit at a given time. This means that the sum throughput in a MANET cannot increase to service additional users. Such MAC protocols disregard the possibility that by utilizing multiple antenna processing to handle interference intelligently at the Physical layer (PHY),...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.