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.
Compared with the small overhead of data payload in sensor network, the overhead of MAC address is significant from the point of view of energy-saving. A distributed algorithm (virtual grid spatial reusing-VGSR) for MAC address assignment is presented in this paper, which is a low energy cost algorithm and reduces the size of the fixed MAC address greatly based on the mapping of geographical position...
This system focuses on a location-aware computing application and environment which provide preemptive information on dangerous locations in the kid's surroundings; i.e., the system alerts a kid on the move of the possible dangers whenever he/she is near accident prone areas. Using satellite-based GPS position sensing, this system can gradually learn and remember about the different locations that...
Many support methods based on learner's learning behaviors and psychological states have been proposed with the progress on Web-based learning. However, the learning in real world is the most important part in one's learning. Researches on learning support methods in real world become possible and necessary with the progress on the ubiquitous techniques. In this paper, we propose a hierarchy of zones,...
Context is the information, which is created and obtained from the surrounding environment for the interaction between humans and computational services. A generic model is a key accessor to the context in any context-aware applications for ubiquitous computing. In the past decades, a number of context modeling techniques have been proposed e.g. markup scheme based, logic-based, graphical, and ontology-based...
Several techniques and applications have been proposed to aid the decision taking process in the system performance domain. Most of these techniques have depicted the performance model of systems through annotations of performance measurements coming from specific software descriptive syntactical languages. However, the semantic representation of performance information provides the possibility of...
We analyze the execution time of MAC-layer Reed-Solomon decoding in cdma2000 1xEV-DO broadcast and multicast services (BCMCS), using different cache sizes and a simulated air channel. MPEG-4 video is widely used for wireless multimedia services; however, it requires successive frames within a specific time interval, which can be missed by a MAC-layer Reed-Solomon decoder due to its computation time...
The physical and logical structures of next generation network and service environment is complex and requires increasingly sophisticated and complicated tools to be fully controllable and well managed. The main problem that has risen is that the old telemanagement model has not enough flexibility to manage rapidly and constantly changing network environment. 3G and 4G networks are basically IP based...
GroupBy-Join queries in SQL are queries involving the group by clause joining several tables. In this paper, we describe three parallelization techniques for GroupBby-Join queries, particularly the queries where the group-by clause can be performed before the join operation. We subsequently call this query "GroupBy-Before-Join" queries. Performance evaluation of the three parallel processing...
The development of large, open, and heterogeneous distributed systems is becoming increasingly dependent on event services to bind together the components of an application in such a way that they are able to react to changes in other components. One way to distribute event notifications around a distributed environment is to use content-based publish/subscribe communication. Such a system mediates...
Improving search performance is an important issue in peer-to-peer (P2P) network systems. Although distributed hash tables (DHTs) route queries more efficiently than flooding does, it's complicated for DHTs to support keyword-based searches. Emerging large-scale P2P systems employ clustering to reduce message overheads and provide system scalability. In this paper, we propose an architecture based...
In P2P systems, the speed of searching for desired lists of sharable files is one of the most important measurement issues in evaluation of overall system performance. Although the searching schemes of existing non-structured P2P systems have been improved to enhance speed considerably, they still never reach to the level of those of the centralized and structured systems. In this paper, we propose...
Network processors (NPs) are set to play a key role in the next generation of networking technology. They have the performance of ASIC-based routers whilst offering a high degree of programmability. However, the programmability potential of NPs can only be realized with appropriate software. In this paper, we argue that specialized software to support runtime reconfiguration is needed to fully exploit...
In process of networks convergence traditional network management systems have been replaced by variety of standards. Also, new principles of management have been emerged. Regarding to these changes new alternative network management techniques is needed. There are a lot of efforts in management protocols improvement based on advanced computer simulation techniques. But, there is a lack in development...
Advances in the area of wireless sensor networks enable a myriad of new applications. Communication is however still the most costly function in these networks. Regions with higher node density lead to a greater amount of energy waste through overhearing, collisions, etc., while not increasing the network's capacity. Therefore, we propose an emergent approach to topology control reducing the number...
In this work, we present a cross-layer forwarding strategy (CLFS), which is based on the cooperation between the new IEEE 802.11e MAC protocol (EDCA) and the on-demand AODV routing protocol. The proposal aims to minimize the number of forwarding nodes (FN) by hop, in the network. By this way, we decrease the contention amount and we improve the medium utilization. The selection of FN is based on maximum...
The paper proposes an RCA MAC protocol to reduce RTS collisions. The protocol utilizes a narrow band, called the tone channel, to announce the RTS transmission in advance to preclude the RTS transmissions of two-hop neighbors. To reduce the channel and hardware overhead, an improvement to the RCA protocol is also devised, which only uses a single channel and one transceiver to reduce RTS collisions...
Dynamic data replication improves data accessibility in mobile ad hoc networks. In our previous works, we proposed few methods to manage locations of replicas and efficiently forward access requests to the locations. In this paper, we extend these methods to adapt to an environment where data items are updated. The extended methods predict the locations of data items by storing and using the information...
Conventionally, many researchers and experts are only focused on studies of routing protocol over the MANET. Currently, the pervasion of Internet applications causes TCP as the standard transmission protocol for most of the networking applications. For the reliable packets delivery, TCP can support the mechanisms of flow and congestion control. Due to the unconstrained movement of the mobile nodes,...
This paper describes a light-weight, content-based, functional query language. The mathematical services query language (MSQL) has been developed for querying mathematical Web services described in the mathematical services description language (MSDL) and published in the MathBroker registry. Based on a client query, MSQL uses the registry to retrieve a candidate collection of documents and then uses...
The growing application of caching in Internet applications have heretofore relied largely on qualitative observation and empirical data on the update behavior of Internet data in their design. While it is empirically known that the update behavior of such data is distinctly bimodal, much less is known about the details of these behaviors and the processes that drives them. A detailed study of the...
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.