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This paper introduces the key aspects of a new channel model based upon the Wireless World Initiative New Radio (WINNER)+ channel model for wireless channels in heterogeneous scenarios (e.g. indoor, outdoor and satellite scenarios). It consists of a collection of features created in the extended spatial channel model (SCME) and WINNER projects along with novel modeling approaches. The quasi deterministic...
This paper presents the study of an access point (AP) deployment strategy which aims to reduce the energy expenditure of ubiquitous motorway network coverage while ensuring Quality of Service (QoS) requirements are maintained at acceptable levels. For this reason, we, in this paper, study the consumption of energy in a scenario where three operational APs are deployed on a motorway with and without...
With the rapid growth of high data rate applications, significant amount of energy is consumed by base stations' equipment. In order to save energy, it is better to deploy fewer base stations (BSs) or switch off as many as possible. However, this is usually attained at the expense of quality of service (QoS). In this paper, we deploy fewer BSs to reduce energy consumption and study the performance...
Delay tolerant network, because of the unreliability of the link, and the limit of the network resources, needs to select the appropriate data forwarding algorithm to ensure efficient message forwarding and delivery. According to DTN properties, this article first establishes the DTN two-layered mobility model. Then it introduces node's location, direction of movement and other important parameters...
A new scheme that serves to find a routing path for Wireless Sensor Networks (WSNs), with a view to facilitate an increase in the network life time is proposed in this paper. It envisages the network to be in the form of clusters and develops an algorithm for transfer of information within the nodes and to the remote Base Station (BS). The approach involves the use of Ad-hoc On Demand Distance Vector...
In order to construct the highway networks, the road tunnels become an inevitable deign to accommodate physical environment elements (e.g., mountains and rivers) in the world. For the recent constructed tunnels, the communication system within the tunnel is planed and designed ahead of time. However, the cost to build and maintain a complete communication system for existing tunnels may not be a cost...
In this paper, a kind of novel alarming access scheme is proposed for the pervasive and mobile healthcare application. This algorithm makes use of the wasted bandwidth in Contention Free Period in order to reduce transmission latency of alarming packets. The performance evaluation shows that this scheme can reduce the delay time of the alarming frame, especially in handling the time-critical problem...
OWD is becoming increasingly important nowadays, as SLA agreements use it as a parameter to ensure QoS levels. However, its measurement is still a much debated topic due to the difficulty in the clock synchronization process. The paper approaches a new methodology to measure OWD, using NTP protocol with virtual clocks and bigger packets. This approach works over a measurement tool developed by the...
This paper proposes a learning approach to solve adaptive Connection Admission Control (CAC) schemes in future wireless networks. Real time connections (that require lower delay bounds than non-real-time) are subdivided into hard realtime (requiring constant bandwidth capacity) or adaptive (that have flexible bandwidth requirements). The CAC for such a mix of traffic types is a complex constraint...
In mobile wireless sensor networks where sensor nodes are general mobile terminals equipped by vehicles and pedestrians, it is difficult for applications to estimate coverages of sensor nodes due to their mobility. In addition, when a network is sparse, it is also difficult to estimate delivery delays of sensor readings to the sink node(s) because delays depend on both the distribution of nodes and...
Content sharing, dissemination and collaboration in open environments require the ability to send and combine data packets across network even in the absence of an end-to-end connected path [1]. User mobility plays a fundamental role in selection of intermediate relays for multi-hop communication [2]. Current schemes do not take into account the effect of power law distribution of inter-contact times,...
In wireless communication, the discovery of the surrounding access points is crucial to provide seamless connectivity to mobile users. In IEEE 802.11, this discovery process is performed by passive and active scanning functions. For both, timers are usually constant (within the 802.11 driver) and their configuration affects the two main scanning performance metrics, i.e., scanning latency and scanning...
End-to-end QoS is a challenge for future Internet. A per flow resource reservation can be carried out among heterogeneous domains on the communication path using signaling protocols. When one or both communicating terminals are mobile there is additional complexity. Signaling delays and resource lacking on future paths can dramatically impact user experience. In this paper, a rational future path...
IP reconfiguration using DHCP is the usual approach followed by mobile nodes (MNs) when they roam from one network to another one. However, DHCP is too slow for cooping with fast handover requirements. This article describes a cross-layer approach for accelerating DHCP-based IP reconfigurations in a mobility scenario across 802.11 access points (APs). DHCP transactions are initiated by neighboring...
A multimedia applications processor is fabricated using a 28nm low-power process technology for ultra-low-power applications. Based on a 4-issue, 32 register version of the TMS320C64X+ VLIW DSP, this System on Chip (SoC) includes 32kB L1 and 128kB L2 caches, and I2S, SPI, UART, MultiMediaCard, and external memory interfaces (Fig. 7.5.1). The design incorporates over 600k instances of custom low-voltage...
We study joint estimation of multipath parameters from orthogonal frequency division multiplex signals transmitted over doubly dispersive mobile radio channels. In particular, we study the joint estimation of the complex gain, delay and Doppler offset of each tap of the multipath channel impulse response. For such channels, the frequency domain channel coefficients for an entire packet can be expressed...
Due to the limited bandwidth of the mobile network, mobile IPTV does not broadcast the content of all channels to its users. The channel zapping time, which is inevitable time until the user watches the display of the selected channel when the selected channel is not available at the mobile device, significantly affects the QoS (Quality of Service) of mobile IPTV services. This paper presents a simple...
We propose a new clock duty control for the mobile display interface. This is designed by using the relation between the data and the strobe signals. The proposed scheme has an output duty error less than 5% for 20% skew and has under 20ps jitter from 500MHz to 1GHz operation.
A common assumption in intermittently-connected (or opportunistic) mobile networks is that any contact has enough capacity to transfer the required amount of data. Although such an assumption is reasonable for analytical purposes and when contents are small, it does not hold anymore when nodes produce contents that are larger than the capacity of a contact. In such a case, nodes must slice data and...
Quality of Service (QoS) of video streaming service over wireless and mobile network is determined by many intermingled factors. Some of the factors can be adjusted. Video resolution, audio rate, and bandwidth are among of them. Other factors are not fully controllable such as network throughput, delay, and packet lost probability. In order to increase user satisfaction, efforts to make better quality...
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