Periodic packets in energy-aware wireless networks

The Global energy consumption and carbon footprint related to operating mobile phones in wireless networks is increasing significantly. In order to determine the overall energy consumption of a wireless network, both the operation of the network infrastructure and the devices connected to that network must be considered. Although the larger part of the global energy consumption of wireless networks is consumed at base station sites and access points, a significant part is consumed from the operation of mobile phones. In this paper, system level power consumption models for mobile phones in terms of 2G, 3G and Wi-Fi are presented. The developed model increases the accuracy of the current power profiles by considering different stages of a single transmission, including the variables affecting each stage. The power states of wireless interfaces, maintenance, network attachment/detachment and network resource allocation policies of different network operators are also considered to obtain a complete model that can accurately predict that power consumption at every stage of connectivity. A comparison between power consumption of different radio access technologies is also included to promote energy efficient use of spectrum. Using the system level power models presented in this paper, the contribution of the operation of mobile phones to overall energy consumption of wireless communication networks can be determined.

IP transition is one of the innovative and challenging areas for the researchers in the recent times. Presently, the transition scheme in Advanced Dual Stack Transition Mechanism (ADSTM) is consuming more time in wireless networks, which impede in general performance of the network. This paper discusses the fast transition of IPV4 packets to IPV6 packets in the Wireless networks via ADSTM. To enhance the performance of ADSTM in wireless network, it is incorporated with the Super Fast Packet Transmission Algorithm (SFTPA). In SFTPA instead of Internet Protocol Header Compression (IPHC) algorithm it is replaced with Robust Header Compression (ROHC) algorithm for better compression, which will reflects in the fast transmission of data packets in Wireless Networks. Simulation experiments were conducted on both the DSTM and ROHC individually and later on their results were merged for the better performance. This work proves that SFTPA has performed better than Fast Packet Transition Algorithm (FPTA) without hampering the Quality-of-Service.

Tail asymptotic behaviour of resequencing buffer content for selective repeat ARQ

In this paper we propose a fair-scheduling algorithm for the transmission of video frames over wireless links. The scheme is based on the occupancy of the video decoder buffer. When the occupancy of the decoder buffer of a given video client becomes increasingly small and approaches a starvation threshold, it gets treated with a higher priority and gets serviced more frequently than other clients who may not be approaching the starvation point. When compared to other commonly-used scheduling algorithms, ours shows a better performance in terms of the end-to-end delay experienced by the video frames.

Finite-state Markov chain (FSMC) models have often been used to characterize the wireless channel. The fitting is typically performed by partitioning the range of the received signal-to-noise ratio (SNR) into a set of intervals (states). Different partitioning criteria have been proposed in the literature, but none of them was targeted to facilitating the analysis of the packet delay and loss performance over the wireless link. In this paper, we propose a new partitioning approach that results in an FSMC model with tractable queueing performance. Our approach utilizes Jake's level-crossing analysis, the distribution of the received SNR, and the elegant analytical structure of Mitra's producer-consumer fluid queueing model. An algorithm is provided for computing the various parameters of the model, which are then used in deriving closed-form expressions for the effective bandwidth (EB) subject to packet loss and delay constraints. Resource allocation based on the EB is key to improving the perceived capacity of the wireless medium. Numerical investigations are carried out to study the interactions among various key parameters, verify the adequacy of the analysis, and study the impact of error control parameters on the allocated bandwidth for guaranteed packet loss and delay performance.

A key characteristic of personal area networks (PANs) is the premium placed on reducing the power consumption of device computation and communication. In such an environment some devices may be more capable of communicating with others simply because of their power capability (i.e., reserve). We propose a power-aware routing protocol capable of routing packets in PANs based on power related optimization and device behavior criteria. Our proposal differs from previous work on power consumption in wireless packet networks which typically aim to reduce the overall device usage and energy consumption.

Integration of data networking into traditional voice only systems, such as SINCGARS and HAVEQUICK, is necessary to meet evolving multimedia communication requirements. The success of this integration is dependent on the development of improved channel-access and network protocols that allow simultaneous voice and data information transfer. In previous work we investigated a system design that includes a new waveform and channel-access protocols to support integrated voice and data transmissions in a multiple-hop packet radio network. In this article we present network protocols that support multiple-hop relaying of data packets in a mobile packet radio network. An adaptive forwarding protocol is defined that can respond quickly to local changes in the environment and traffic load. An OPNET simulation, which models the physical, channel-access, and network layers, is implemented to characterize the performance of the network protocols. We show the ability of the network to support relaying of data traffic, and we show the improvement in performance that is achieved through the use of the adaptive forwarding protocol.

The rapid growth of diversified applications has led to significant increase in data traffic and energy consumption in wireless networks. Hence, the energy efficiency becomes one of critical performance indices for designing next-generation wireless networks. In this paper, an optimization framework of power allocation is investigated for maximizing energy efficiency in multiuser relay networks. Under a total power constraint, we formulate the design problem with the objective as the ratio of the spectral efficiency over the entire power consumption of the network. An optimal energy-efficient power allocation algorithm is proposed for the source and the relay nodes to approach the maximum efficiency in an iterative manner. Compared with a heuristic scheme where the total available power is equally allocated to all nodes, the proposed optimal power allocation algorithm can dramatically improve energy efficiency with a slight loss in spectral efficiency.

Fountain coding is a valuable tool for multicast transmissions in half-duplex packet radio networks if it is supported by an adaptive transmission protocol that compensates for fluctuations in the propagation losses on the radio links. Our goal is to devise low-complexity packet-by-packet adaptive modulation and channel coding protocols that provide high throughput for a broad range of multicast channels and operate with limited feedback and no knowledge of the fade levels or even the probability distribution for the fading on the radio links. The only control information for the protocols is derived from simple receiver statistics that are obtained by the demodulators and channel decoders in the receiving radios. Performance results are presented for practical fountain coding with low-complexity adaptive modulation and channel coding. Results on ideal fountain coding with adaptive transmission based on hypothetical perfect channel-state information are employed as performance benchmarks.

Future wireless systems are being designed for extremely high data rates and are directly contributing to the global energy consumption. This trend is undesirable not only due to the environmental concerns, but to cost as well since energy costs are becoming a significant part of the operating expenditures for the telecom operators. Recently, energy efficient wireless systems have become a new research paradigm. Cooperative communication has shown good potential in improving coverage, providing robust radio links, reducing infrastructure cost, and has the possibility to reduce the total system energy consumption. This paper looks at possible deployment strategies for wireless networks that can reduce the energy consumption. We look at the tradeoff between the number of relay nodes and the number of base stations and their implications on the total energy consumption of wireless networks. The obtained results show that adaptive resource allocation between the base station and the relay node is an efficient way of reducing the energy consumption of the system. Furthermore, this reduction in energy consumption increases with increasing the system target spectral efficiency.

The demand to reduce energy consumption in wireless networks has become popular recently. In this paper, aimed at the problem that how to reduce energy consumption through on-off control in wireless networks without losing system performance significantly, we present our solution both in a single base station and the multi-base station scenario. Under the assumption that the network arrival and departure process are Markov, we first model and solve the problem of optimal on-off control in single base station scenario using dynamic integer programming (DIP) method, then we extend the optimal solution to multi-base station scenario and raise an effective heuristic method in two layer networks, the trade-off between QoS level and energy consumption has been given according to our analysis and simulation. Numerical results are provided to demonstrate that the proposed method offer significant gain in terms of the energy efficiency.

As 4G wireless networks are vastly and rapidly deployed worldwide, 5G with its advanced vision of all connected world and zero distance communications is already at the corner. Along with the super quality of user experience brought by these new networks, the shockingly increasing energy consumption of wireless networks has become a worrying economic issue for operators and a big challenge for sustainable development. Green Transmission Technologies (GTT) is a project focusing on the energy-efficient design of physical-layer transmission technologies and MAC-layer radio resource management in wireless networks. In particular, fundamental tradeoffs between spectrum efficiency and energy efficiency have been identified and explored for energy-efficiency-oriented design and optimization. In this article, four selected GTT solutions are introduced, focusing on how they utilize the degrees of freedom in different resource domains, as well as how they balance the tradeoff between energy and spectrum efficiency. On top of the elaboration of separated solutions, the GTT toolbox is introduced as a systematic tool and unified simulation platform to integrate the proposed GTT solutions together.

Reducing the energy consumption of wireless networks is one of the fundamental objectives of green networks. While the use of dynamic frequency scaling has been proposed for reducing the energy consumption, they increase the packet delays and loss rates in the network. This paper addresses the problem of optimally selecting the clock frequency for wireless network interface cards with dynamic frequency scaling, so that the energy consumption is minimized while meeting the packet level performance requirements. The proposed framework is based on modeling the interface card as a MAP/G/1/K with threshold based service. The proposed frequency selection mechanism has been verified through simulations.

Recently, the cooperative communication has been explored more and more as an impressing technique to combat the effects of channel fading and to reduce the energy consumption in wireless networks. However, the impact of cooperative communications on transmission rate has not been well-addressed yet. In this paper, we provide an analytical framework for transmission rate enhancement issue in wireless communications. For a given transmit power and a desired probability of success, we investigate how much average transmission rate can be increased by cooperative communications. Three transmission models have been compared: the direct transmission, the cooperative transmission without maximal ratio combiner (MRC), and cooperative transmission with MRC. The analytical and numerical results show that around 1 - 3b/s/Hz transmission rate can be improved when the source-destination distance is 20m. We also reveal that the MRC scheme is not always beneficial, especially when the source-destination distance is short and the relay is close to the destination.

Under given energy constraints, a fundamental problem in wireless networks is to maximize network lifetime and prolong network operational lifetime. Since nodes in the network can be affected with interference of peripheral nodes, it causes collisions and congestions. Thus, whole network consumes more energy. It is clear that the higher density of network the higher degree of nodes. It leads to more redundant coverage, i.e. more overlapped areas (joint areas between adjusted nodes) in the network, which also increases energy consumption and probability of collisions. This paper proposes an energy-efficient topology control algorithm. Based on location awareness, the proposed algorithm minimizes a set of the relay nodes keeping the connectivity and whole network coverage. To address this, the algorithm calculates density of network and divides the transmission range of a node into border area and core area. Then, the algorithm calculates overlapped areas between border nodes and selects relays amongst them. As a result, the network can be seen as a sparse network in which the overlapped areas are reduced. Since only selected nodes act as relays at the particular time interval, it helps to reduce whole network energy consumption, prolong operational network lifetime and reduce collisions or congestions. The results of simulation show that the proposed algorithm improves energy-efficiency of the network while preserving connectivity and functions of routing agent.