Physical Wireless Network Research Articles

Virtual network embedding method based on node delay perception

AbstractWireless virtual network uses software defined network and network function virtualisation technologies to create multiple logically isolated virtual networks on a physical wireless network. Wireless virtual network can improve the utilisation of wireless resources to meet the requirements of different services. Delay is an important performance indicator, which has strict requirements for delay‐sensitive services such as video conferencing and online games. In this study, a virtual network embedding method based on node delay perception (VNE‐NDP) is proposed, which considers both the node and link resources as well as the embedding delay requirements of virtual networks. The virtual network embedding method based on node delay perception consists of two phases: virtual node embedding and virtual link embedding. In the virtual node embedding phase, a physical node sorting method based on node delay perception (PNS‐NDP) is proposed. In PNS‐NDP, the node deployment delay is introduced into the node sorting algorithm for the first time. The authors select candidate physical nodes for each virtual node according to their resource availability and delay performance, which can greatly reduce the VN embedding delay without sacrificing too much other performance. In the virtual link embedding phase, a shortest path algorithm with bandwidth and link deployment delay constraints to find feasible physical paths for each virtual link is used. In addition, the VN embedding (VNE) deployment time is set as a new evaluation index. Simulation results show that compared with other VNE methods, VNE‐NDP can achieve higher success rate, revenue‐to‐expenditure ratio, and lower deployment delay.

Reliable Wireless Networking via Soft-Source Information Combining

This article puts forth a multistream networking paradigm, referred to as soft-source-information-combining (SSIC), to support wireless Internet of Things (IoT) applications with ultrareliability requirements. For SSIC networking, an SSIC dispatcher at the source dispatches duplicates of packets over multiple streams, which may be established over different physical wireless networks. If a packet on a stream cannot be decoded due to wireless interference or noise, the decoder makes available the packet’s soft information. An aggregator then combines the soft information of the duplicates to boost reliability. Of importance are two challenges: 1) how to descramble the scrambled soft information from different streams to enable correct SSIC and 2) the construct of an SSIC dispatching and aggregation framework compatible with commercial network interface cards (NICs) and TCP/IP networks. To address the challenges, we put forth: 1) a soft descrambling (SD) method to minimize the bit-error rate (BER) and packet-error rate (PER) at the SSIC’s output and 2) an SSIC networking architecture readily deployable over today’s TCP/IP networks without specialized NICs. For concept proving and experimentation, we realized an SSIC system over two Wi-Fi’s physical paths in such a way that all legacy TCP/IP applications can enjoy the reliability brought forth by SSIC without modification. Experiments over our testbed corroborate the effectiveness of SSIC in lowering the packet delivery failure rate and the possibility of SSIC in providing 99.99% reliable packet delivery for short-range communication.

Game-Theory Based Power and Spectrum Virtualization for Optimizing Spectrum Efficiency in Mobile Cloud-Computing Wireless Networks

Mobile cloud-computing is a wireless network environment that focuses on sharing the publicly available wireless resources. Wireless network virtualization provides an efficient technique to implement the mobile cloud-computing by enabling multiple virtual wireless networks to be mapped onto one physical substrate wireless network. One of the most important challenges of this technique lies in how to efficiently allocate the wireless resources of physical wireless networks to the multiple virtual wireless network users. To overcome these difficulties, in this paper we propose a set of novel game-theory based schemes to resolve the wireless resources allocation problem in terms of transmit power and wireless spectrum. We formulate this wireless resources allocation problem as the gaming process where each mobile user bids for the limited wireless resources from physical substrate wireless networks, and competes with the other mobile-user players bidding for the same resources. Under our proposed game-theory framework, we develop three types of wireless resources request strategies: price-based strategy, correlation-based strategy, and water-filling-based strategy to allocate wireless resources under three different gaming mechanisms. The extensive simulation results obtained validate and evaluate our proposed schemes.

Imagining Future Cities: Aesthetic Design Guidelines for Wireless Small Cells in Urban Landscapes

Wireless towers with big antennas and large equipment shelters are decreasing as the primary type of wireless infrastructure in favor of more diversified designs, varying in size, network architecture, and capacity. The definitional boundary between typical macro sites of the 1990s and increasingly popular small cell networks are slowly blending as the backend architecture and the equipment on a site are designed to meet a greater variety of capacity and coverage needs through heterogeneous networks. As the design of wireless network architecture is changing, so are their appearance in our surrounding environment. As a result, municipal authorities are increasingly under pressure by the Federal Communication Commission (FCC) and wireless carriers to adapt and evolve their siting and permitting practices to accommodate a variety of different types of facilities. This paper will evaluate how innovation in LTE and 5G equipment is changing the design of physical wireless networks, establish an understanding of ‘contextual appropriateness’ in the blending of new small cells with the previously built environment, and prescribe aesthetic design guidelines for improving people’s experience with new urban wireless facilities. The methodology will include identifying technological trajectories and possibilities in wireless small cell designs, categorization of existing available assets for their deployment, an analysis of contextual appropriateness, and the development of objective design principles that will facilitate structured guidelines for network deployment. First, the paper will consider how wireless network equipment is evolving in different types of network topologies. Second, as small cells are typically placed on poles, these deployments will be categorized based on commonly available vertical assets in the Rights of Way, types of street furniture available for small cell integration opportunities, and other types of design ideas that leverage existing structures. Third, the definition of contextual appropriateness will be examined through city planning and architectural integration principles and typical constraints within the urban landscape. This paper will heavily utilize visual examples of previously deployed designs to analyze their technological components, design elements, and methods of construction and composition. Many of these visual examples are available in FCC docket filings relating to the recent relevant proceedings (WT Docket 17-79 and related), as well as in many articles and online government resources. Fourth, this research will contribute to a systematic method of evaluating the quality of small cell designs on a methodical basis, replacing the existing common practice of relying on subjective, improvised, and often contradictory aesthetic preferences. The resulting design recommendations and architectural best practices will facilitate many local efforts to develop preferential guidelines that achieve long-term compromise between preserving the character of their community and advancing to the smart cities of the future. The guidelines will also promote a more positive public perception and a more welcoming attitude toward the widespread integration of wireless facilities. The way that wireless technology will become deployed in the future of a given urban neighborhood will become its history, its character, and its legacy for advanced technological systems yet to come.

A Social-Aware Framework for Efficient Information Dissemination in Wireless Ad Hoc Networks

In wireless ad hoc networks, each node participates in routing by forwarding data to other nodes without a pre-existing infrastructure. Particularly, with the wide adoption of smart devices, the concept of smartphone ad hoc networks (SPANs) has evolved to enable alternate means for information sharing. Using unlicensed frequency spectrum and short-range wireless technologies, a SPAN enables a new paradigm of applications and thus is seen as an attractive component in future wireless networks. In a SPAN, smartphones form local peer-to-peer networks to cooperate and share information efficiently. Recent studies have shown that if the users’ social relations are considered while designing cooperation schemes and protocols in SPANs, the cooperation initialization and content dissemination can be notably improved to increase the overall network efficiency and communications reliability. In this article, we present a social-aware framework for optimizing SPANs by exploiting two layers: users’ relationships in the online social network layer and users’ offline connections and interactions in the physical wireless network layer. The online content popularity distribution is also studied as a result of the users’ online interaction profiles. In the end, we integrate both online and offline layers, and discuss possible applications to further enhance the network performance.

Social Network Aware Device-to-Device Communication in Wireless Networks

Device-to-device (D2D) communication is seen as a major technology to overcome the imminent wireless capacity crunch and to enable new application services. In this paper, a novel social-aware approach for optimizing D2D communication by exploiting two layers, namely the social network layer and the physical wireless network layer, is proposed. In particular, the physical layer D2D network is captured via the users' encounter histories. Subsequently, an approach, based on the so-called Indian Buffet Process, is proposed to model the distribution of contents in the users' online social networks. Given the social relations collected by the base station, a new algorithm for optimizing the traffic offloading process in D2D communications is developed. In addition, the Chernoff bound and approximated cumulative distribution function (cdf) of the offloaded traffic are derived and the validity of the bound and cdf is proven. Simulation results based on real traces demonstrate the effectiveness of our model and show that the proposed approach can offload the network's traffic successfully.

Opportunistic sharing scheme for spectrum allocation in wireless virtualization

The past few decades have witnessed an increasing growth in mobile and wireless network, leading to a corresponding fast growth in mobile demands. However, the proliferating mobile demands compel wireless network to face several challenges, such as the conflict between spectrum crisis and low resource utilization ratio, and the poor quality of service and quality of experience. Wireless virtualization, enabling multiple concurrent virtual networks running on shared wireless substrate resource, has been proposed as a promising way to overcome the plights of the current mobile and wireless network. How to efficiently allocate the resource, especially the spectrum resource, of physical network to multiple virtual networks is one fundamental and important challenge in wireless virtualization. This paper rethinks the characteristics of virtual networks' requirements, and then divides the requirement into a baseline part and a fluctuant part. Based on it, this paper introduces an opportunistic spectrum sharing approach, through which we formulate the spectrum resource allocation problem as an NP-Hard problem. Then, we propose our opportunistic spectrum resource allocation scheme for the wireless virtualization. Simulations validate the performance advantages of our approach and show that opportunistic spectrum sharing significantly improves the revenue, resource utilization and acceptance ratio of physical wireless network while decreasing the payments of virtual networks.

An Elastic Sub-carrier and Power Allocation Algorithm Enabling Wireless Network Virtualization

Wireless mobile network virtualization enables physical mobile network operators (PMNO) to partition their network resources into smaller slices and assign each slice to an individual virtual mobile network operator and then manages these virtual networks in a more dynamic and cost-effective fashion. How a PMNO allocates resources to individual slices while ensuring resource elasticity is a key issue. This paper presents a resource allocation algorithm in such a network virtualization scenario where resource considered here includes both sub-carriers and transmission power. The overall algorithm involves the following two major processes: firstly to virtualize a physical wireless network into multiple slices each representing a virtual network, where resources are allocated elastically based on traffic loads and channel state information during virtualization; secondly, to carry out physical resource allocation within each virtual network (or slice). In particular the paper adopts orthogonal frequency division multiplexing as its physical layer to achieve more efficient resource utilization. A multi-step dynamic optimization approach is proposed to achieve sub-carrier allocation using binary integer programming and power allocation using nonlinear programming. The aim is to achieve the following design goals: virtual network isolation, and resource efficiency. The simulation results show that the above goals have been achieved.

An elastic resource allocation algorithm enabling wireless network virtualization

Following the wired network virtualization, virtualization of wireless networks becomes the next step aiming to provide network or infrastructure providers with the ability to manage and control their networks in a more dynamic fashion. The benefit of the wireless mobile network virtualization is a more agile business model where virtual mobile network operators MNOs can request and thus pay physical MNOs in a more pay-as-you-use manner. This paper presents some resource allocation algorithms for joint network virtualization and resource allocation of wireless networks. The overall algorithm involves the following two major processes: firstly, to virtualize a physical wireless network into multiple slices, each representing a virtual network, and secondly, to carry out physical resource allocation within each virtual network or slice. In particular, the paper adopts orthogonal frequency division multiplexing OFDM as its physical layer to achieve more efficient resource utilization. Therefore, the resource allocation is conducted in terms of sub-carriers. Although the motivation and algorithm design are based on IEEE 802.16 or WiMAX networks, the principle and algorithmic essence are also applicable to other OFDM access-based wireless networks. The aim was to achieve the following design goals: virtual network isolation and resource efficiency. The latter is measured in terms of network throughput and packet delivery ratio. The simulation results show that the aforementioned goals have been achieved. Copyright © 2012 John Wiley & Sons, Ltd.