01
Apr

A Collision Avoidance Scheme for the Synchronized Broadcast Packets in a Multi-AP Wi-Fi Broadcasting System

A Wi-Fi broadcasting system is a kind of Mobile-TV system that transmits multimedia content over Wi-Fi networks. The specialty of the system is that it takes advantage of broadcast packets for streaming to be scalable to the number of users. However, the loss rate of broadcast packets is much higher than that of unicast ones […]

01
Jan

An Energy Efficient Active RFID Protocol to Avoid Overhearing Problem

In this paper we describe an energy efficient protocol for active radio frequency identification (RFID) tags complying with the standard. The energy efficiency is a key requirement for the wider acceptance of the active RFID systems that use battery constrained tags. The existing active RFID protocols try to reduce energy consumption of tags by putting […]

01
Aug

An efficient transmission scheme of MPEG2-TS over RTP for a Hybrid DMB System

Hybrid digital multimedia broadcasting (DMB) is a next‐generation mobile TV system that combines broadcasting and wireless communication networks and can provide various high‐quality multimedia services. However, if a system adheres to the current standard of transmitting the DMB content in the form of MPEG2‐TS through wireless networks, it results in a burden on the network […]

21
May

Design and Implementation of Multi-Rate Broadcast Based Link Quality Measurement for Wireless Mesh Network

We propose MBAP (Multi-rate Broadcast Active Probing) technique to get the right measurements for link quality in Wireless Mesh Network (WMN). Most routing protocols for WMN make use of link quality-aware routing metrics, such as ETX(Expected Transmission Count) and ETT(Expected Transmission Time), while the hop count is usually used in MANET (Mobile Ad-hoc NETwork). A […]

21
May

A Quality Ratio-Based Novel Unequal Loss Protection Scheme in Wi-Fi Broadcasting System

The Wi-Fi broadcast system using the broadcast packet transmits the multimedia contents to many local mobile users in real time and it must use the FEC technology to recover the broadcast packet loss, because Media Access Control layer retransmission is not supported for broadcast packet loss. Equally adding the redundant packet is not very efficient […]

01
Aug

An Efficient and Flexible Hybrid Conditional Access System for Advanced T-DMB

This letter presents a hybrid conditional access system (CAS) for advanced terrestrial digital multimedia broadcasting (AT‐DMB). The proposed architecture is characterized by its use of a unified CAS channel and various communication networks for CAS message transmissions. We implement a prototype CAS based on the hybrid architecture, which improves the CAS message transmission efficiency greatly […]

04
Jul

Enhanced Precision Time Synchronization for Wireless Sensor Networks

Time synchronization in wireless sensor networks (WSNs) is a fundamental issue for the coordination of distributed entities and events. Non-deterministic latency, which may decrease the accuracy and precision of time synchronization can occur at any point in the network layers. Specially, random back-off by channel contention leads to a large uncertainty. In order to reduce […]

27
Jun

Large-Scale Active RFID System Utilizing ZigBee Networks

As the era of the ubiquitous computing is ushered in, consumers have been primed for a variety of automation applications. Active RFIDs can be used for a number of automation applications because it may also have other sensors to extend its applications. An active RFID instinctively focuses on a long communication range. Nevertheless, active RFIDs […]

01
May

Load Balancing for a Multi-Channel Multi-Interface 2.4 GHz Active RFID Reader

ISO/IEC 18000-7 Active RFID standard, a single channel system operating at 433 MHz, faces technical difficulties in supporting some recently introduced application demands because of its low transmission rates and vulnerability to radio interference between the readers. We propose a new multi-channel active RFID system operating at the 2.4 GHz band. The special feature of […]

05
Mar

Geometrical Approach to Multi-Phase RFID Filtering in Dense Environments

In the upcoming ubiquitous computing environment, almost every object that needs to be identified will be attached to an radio frequency identification (RFID) tag. Omnipresent RFID tags lead to the concern that huge volumes of RFID data could easily overwhelm related networks and systems. However, for most applications, only a small subset of ID data […]