Advanced carrier sensing to resolve local channel congestion

Communication performance in VANETs under high channel load is significantly degraded due to packet collisions and messages drops, also referred to as local channel congestion. So far, research was focused on the control of transmit power and the limitation of the messages rate to mitigate the effects of high load. Few attention has been paid to the carrier sensing setup, i.e controlling WHEN the channel is indicated as clear. In previous work, we identified that the Clear Channel Assessment (CCA) as part of the carrier sensing is a very efficient way of controlling the spatial reuse under high load. The CCA threshold determines at which received power level the channel is sensed busy. In this paper, we propose a stepwise CCA Threshold Adjustment (CTA) depending on how long the packet has been waiting already for medium access. This basic and robust approach mitigates significantly the problem of local message queue drops and hence local congestion. The simulation study confirms the reduction of the average and maximum medium access delay as well as the prevention of message queue drops. Even under inaccurate CCA thresholds among the vehicles, fairness in medium access can be maintained by using CTA. In all cases, the awareness of each vehicle is dramatically improved within the safety-critical area of each vehicle

ANALYSIS PROGRAM BUSSINESS DEVELOPMENT SERVICES (BDS) AND EXPANSION OF NETWORK PERFORMANCE MANAGEMENT PRODUCT MARKET FOR SMALL AND MEDIUM ENTERPRISES (UKM) IN THE REGION GERBANGKERTOSUSILA

Some program development support system for cooperative effort, Micro, Small And Medium aims to simplify, accelerate and broaden access Cooperatives, Micro, Small and Medium Enterprises to productive resources to be able to take advantage of the opportunities and potential of local resources to develop KUMKM businesses, as well as adjustment scale its business to be more efficient. Results if the data using the method of AHP and expert choice software assistance to the respondents' answers on a variety of criteria that affect the Program Business Development Services (BDS) Against management Performance Network Expansion Markets And Products For Small and Medium Enterprises (UKM) in Region Gerbangkertosusila

Efficient channel allocation and medium access organization algorithms for vehicular networking

Due to the limited bandwidth available for Vehicular Ad-hoc Networks (VANETs), organizing the wireless channel access to efficiently use the bandwidth is one of the main challenges in VANET. In this dissertation, we focus on channel allocation and media access organization for Vehicle-to-Roadside Units (V2R) and Vehicle-to-Vehicle (V2V) communications. An efficient channel allocation algorithm for Roadside Unit (RSU) access is proposed. The goal of the algorithm is to increase system throughput by admitting more tasks (vehicles) and at the same time reduce the risk of the admitted tasks. The algorithm admits the new requests only when their requirements can be fulfilled and all in-session tasks\u27 requirements are also guaranteed. The algorithm calculates the expected task finish time for the tasks, but allocates a virtual transmission plan for the tasks as they progress toward the edges of the RSU range. For V2V mode, we propose an efficient medium access organization method based on VANETs\u27 clustering schemes. In order to make this method efficient in rapid topology change environment like VANET, it\u27s important to make the network topology less dynamic by forming local strongly connected clustering structure, which leads to a stable network topology on the global scale. We propose an efficient cluster formation algorithm that takes vehicles\u27 mobility into account for cluster formation. The results of the proposed methods show that the wireless channel utilization and the network stability are significantly improved compared to the existing methods

Compressive Sensing Medium Access Control for Wireless LANs

We propose a medium access control (MAC) protocol for wireless local area networks (LANs) that leverages the theory of compressive sensing. The proposed compressive sensing MAC (CS-MAC) exploits the sparse property that, at a given time, only a few hosts are expected to request for radio channel access. Under CS-MAC, a central coordinator, such as a wireless access point (AP) can recover a multitude of these requests in one decoding operation, and then schedule multiple hosts accordingly. The coordinator is only required to receive a relatively small number of random projections of host requests, rather than polling individual hosts. This results in an efficient request-grant method. Via a hardware prototype based on a software-de ned radio platform, we demonstrate the feasibility of realizing CS-MAC with compressive measurements formed in the air to achieve high efficiency.Engineering and Applied Science

Small and Medium Enterprises and Economic Growth in Nigeria

This paper seeks to investigate Small and Medium Enterprises as a veritable tool in Economic Growth and Development. A survey method was used to gather data from 200 SME/Entrepreneurial officers and Managers from five selected local government in Nigeria namely; Ijebu North, Yewa South, Sagamu, Odeda and Ogun Waterside Local government. Data was collected with a structured questionnaire and analyzed with several descriptive statistics to identify the perception of the roles of SMEs in Nigeria. The results of the study therefore reveals that the most common constraints hindering small and medium scale business growth in Nigeria are lack of financial support, poor management, corruption, lack of training and experience, poor infrastructure, insufficient profits, and low demand for product and services.  Hence, it therefore recommends that Government should as matter of urgency assist prospective entrepreneurs to have access to finance and necessary information relating to business opportunities, modern technology, raw materials, market, plant and machinery which would enable them to reduce their operating cost and be more efficient to meet the market competitions

Network reliability

Network control (or network management) functions are essential for efficient and reliable operation of a network. Some control functions are currently included as part of the Open System Interconnection model. For local area networks, it is widely recognized that there is a need for additional control functions, including fault isolation functions, monitoring functions, and configuration functions. These functions can be implemented in either a central or distributed manner. The Fiber Distributed Data Interface Medium Access Control and Station Management protocols provide an example of distributed implementation. Relative information is presented here in outline form

Segmenting citizens according to their self-sufficiency:A tool for local government

Identifying subgroups of citizens with varying levels of self-sufficiency in a large local or regional population provides local government with essential input for providing matching services and well-grounded spending of health and well-being expenditures. This paper identifies self-sufficiency levels of citizens by segmenting a broad adult population. We used data from a citizen survey based on a randomly selected response group containing questions on a wide range of topics, including finances, health and living conditions, and complemented these data with registration data, including information on housing type and household composition. We conducted a latent class cluster analysis using six indicators: perception of making ends meet, perceived health, quality of life, self-efficacy, access to social support and social network. High scores on the indicators translate to high levels of self-sufficiency. We used a biased-adjusted, three-step approach to characterise the segments. Six meaningful segments were identified and labelled as ‘highly self-sufficient,’ ‘self-sufficient – medium access to social support,’ ‘self-sufficient – medium self-efficacy,’ ‘moderately self-sufficient – low self-efficacy &amp; high social network,’ ‘moderately self-sufficient – low access to social support/social network &amp; high perceived health’ and ‘not self-sufficient.’ At a macro level, perception of making ends meet and quality of life have discriminating value in assessing self-sufficiency. For a more detailed differentiation between groups with similar levels of self-sufficiency, perceived health, self-efficacy, access to social support, and social network are valuable indicators. Overall, this study introduces a comprehensive tool to assess self-sufficiency in larger groups of citizens by using a parsimonious number of indicators. Local and regional governments can apply this tool to effectively assess the self-sufficiency levels of their population and signal potentially vulnerable groups. In this way, the tool makes the identification of self-sufficiency levels of larger populations more feasible and more efficient and can be widely adopted in different contexts.</p

A dynamic programming algorithm for the local access network expansion problem

Technological innovations and growing consumer demand have led to a variety of design and expansion problems in telecommunication networks. In particular, local access net- works have received a lot of attention, since they account for approximately 60% of total investments in communication facilities. In this paper we consider the Local Access Network Expansion Problem, in which growing demand can be satisfied by expanding cable capacities and/or installing concentrators in the network. The problem is known to be NP-hard. We present a pseudo-polynomial dynamic programming algorithm, with time complexity O( nB²) and storage requirements O( nB ), where n refers to the size of the network, and B to an upper bound on concentrator capacity. The cost structure in the network is assumed to be decomposable, but may be non-convex, non-concave, and node and edge dependent otherwise. Computational results indicate that the algorithm is very efficient and can solve medium to large scale problems to optimality within (fractions of) seconds to minutes.mathematical economics and econometrics ;