Mobile Computing and Communications Review最新文献

{"title":"Scanning the literature","authors":"E. D. Lara","doi":"10.1145/997122.997124","DOIUrl":"https://doi.org/10.1145/997122.997124","url":null,"abstract":"This paper investigates the use of peer-to-peer networking, also known as ad hoc networking, to increase cell capacity and reduce energy consumption for Internet access in cellular wireless data networks. The paper shows that a direct application of the peerto-peer network model to Internet access in cellular networks significantly degrades network throughput, and results in unfair bandwidth allocation across network flows. The reduction in network throughput results from the overheads and inefficiencies of the peer-to-peer protocols. Whereas cellular network protocols are centralized and operate over a single hop, peer-to-peer protocols, such as IEEE 802.11 DCF and DSR, are distributed and operate over multiple hops. Compared to the centralized protocols, peer-to-peer protocols produce less optimal transmission schedules and increase contention for the wireless medium. Notwithstanding these drawbacks, because peer-topeer relies on short-range transmissions, it achieves lower power consumption and higher throughput per unit power than the centralized cellular protocols. The authors then describe assisted scheduling and dual-mode operation, two techniques that leverage the energy savings of peer-to-peer networking, and match the network throughput of the cellular model. In assisted scheduling, the base station periodically draws up a schedule for multi-hop transmissions within the network that maximizes throughput subject to fair perflow service. The base station devises the schedule based on information provided by mobile hosts about their location and nodes in their neighborhood. In dual-mode operation, the base station simultaneously supports flows that operate either in the peer-topeer mode or the cellular mode. Dual-mode operation allows individual flows in the network to dynamically choose the mode of operation that can provide better service, while the base station provides the two flow modes time-division access to the channel. Initially all flows operate in the peer-to-peer mode. A flow in the peer-to-peer mode switches to the cellular mode if it does not achieve the required network throughput. Once switched to the cellular mode, a flow switches back to the peer-to-peer mode whenever the network state is such that it can achieve the desired throughput. Finally, the paper evaluates the use of multi-homed host that extend the peer-to-peer network model to relay traffic between different networks. Both peer relays that forward traffic between wireless and wired networks, as well as relays that bridge different wireless network technologies, such as 802.11 and 3G, are explored. The multi-homed peer relays relieve the channel bottleneck around the base station (i.e., the base station is no longer the only destination for Internet access), and in doing so translate the spatial reuse benefits of the peer to peer network into better throughput performance.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88040118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scanning the literature","authors":"B. Li","doi":"10.1145/583997.584003","DOIUrl":"https://doi.org/10.1145/583997.584003","url":null,"abstract":"This paper develops a model using a combination of empirical data and theoretical models, to capture the user behavior in a PCS environment. Mobility management is in terms of keeping track of and locating users so that calls arriving for the particular users can be delivered to their current locations, which usually consists of two parts: users notifying the system of the location once moved (updating), and system notifying the users that calls arriving for them (paging). PCS network differs from conventional cellular network in several aspects. For example more stringent QoS requirements from users are expected, and smaller cells to support more users and greater traffic density. As a result the updating and paging traffic have to be carefully managed. To handle the updates, the model presented in this paper combines automatic updated by the users whenever they make significant moves or when they lose network interaction for extended period of time. And a focused paging mechanism is introduced to minimize the number of pages under the constraint of the amount of time allowed to a page. The model shows that over a range of systems and user parameters, the total paging and updating traffic can be kept under 1 per 2000 user seconds, and the impact on the user is less than 10 updates per day. To satisfy the needs of wireless data networking, study group 802.11 was formed under IEEE project 802 to recommend an international standard for Wireless Local Area Networks (WLANs). A key part of standard are the Medium Access Control (MAC) protocol needed to support asynchronous and time bounded delivery of data frames. It has been proposed that unslotted Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) be the basis for the IEEE 802.11 WLAN MAC protocols. This paper conducts performance evaluation of the asynchronous data transfer protocols that are a part of the proposed IEEE 802.11 standard taking into account the decentralized nature of communication between stations, the possibility of \"capture\", and presence of \"hidden\" stations. System throughput is obtained, and fairness properties of the proposed MAC protocols are evaluated. Further, the impact of spatial characteristics on the performance of the system and that observed by individual stations is determined. A comprehensive comparison of the access methods provided by the 802.11 MAC protocol is done and observations are made as to when each should be employed. Extensive numerical and simulation results are presented to help understand the issues involved.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84070327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COAP: A Software-Defined Approach for Home WLAN Management through an Open API","authors":"Ashish Patro, Suman Banerjee","doi":"10.1145/2721896.2721904","DOIUrl":"https://doi.org/10.1145/2721896.2721904","url":null,"abstract":"In recent years, there has been a rapid growth in the adoption and usage of WiFi enabled networked devices at homes such as laptops, handheld device and wireless entertainment devices. In dense wireless deployments at homes, such as apartment buildings, neighboring home WLANs share the same unlicensed spectrum by deploying consumer-grade access points in their individual homes. In such environments, WiFi networks can suffer from intermittent performance issues such as wireless packet losses, interference from WiFi and non-WiFi sources due to the increasing diversity of devices that share the spectrum. In this paper, we propose a vendor-neutral cloud-based centralized framework called COAP to configure, co-ordinate and manage individual home APs using an open API implemented over the OpenFlow SDN framework. This paper describes the framework and motivates the potential benefits of the framework in home WLANs.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83863462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bundle protocol header compression","authors":"M. Wegner, Wolf-Bastian Pöttner, L. Wolf","doi":"10.1145/2645672.2645682","DOIUrl":"https://doi.org/10.1145/2645672.2645682","url":null,"abstract":"Delay Tolerant Networks (DTNs), especially the Bundle Protocol (BP), transmit data in self-contained bundles each of which carrying all necessary information to process it and route it to its destination. While this allows for long delays, link disruptions and higher loss rates and makes the BP well-suited for networks such as Wireless Sensor Networks (WSNs), it imposes a significant overhead in terms of the header sizes, as e. g. node addresses are denoted as full URIs, called Endpoint Identifiers (EIDs).\u0000 While the Compressed Bundle Header Encoding introduces a special naming scheme to eradicate these URIs which reduces the header size to some extent, in this paper we present a novel, full-fledged header compression for the BP that can be applied stateless or stateful, i. e. without or with storing part of the bundle headers on forwarding nodes. The gains achievable with this approach are extensively evaluated with the simulation of bundles carefully generated from real-world network traffic on the one hand, and of realistically moving public transport vehicles with a traffic pattern often found in such Delay Tolerant Wireless Sensor Networks (DTWSNs) on the other hand.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87355970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harmonia: Wideband Spreading for Accurate Indoor RF Localization","authors":"B. Kempke, P. Pannuto, P. Dutta","doi":"10.1145/2721896.2721901","DOIUrl":"https://doi.org/10.1145/2721896.2721901","url":null,"abstract":"We introduce Harmonia, a new RF-based localization scheme that provides the simplicity, cost, and power advantages of traditional narrowband radios with the decimeter-scale accuracy of ultra wideband localization techniques. Harmonia is an asymmetric tag and anchor system, requiring minimal modifications to existing low-power wireless devices to support highfidelity localization with comparatively modest infrastructure costs. A prototype Harmonia design offers location estimates with an average-case error of 53.4 cm in complex, heavymultipath, indoor environments and captures location estimates at 56 Hz while requiring only 1.7 mA additional power draw for each tag and complying with all US UWB regulations. We believe this architecture's combination of accuracy, update rate, power draw, and system complexity will lead to a new point in the design space.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83516432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Brave New World: Privacy Risks for Mobile Users","authors":"Paarijaat Aditya, Bobby Bhattacharjee, P. Druschel, V. Erdélyi, Matthew Lentz","doi":"10.1145/2721896.2721907","DOIUrl":"https://doi.org/10.1145/2721896.2721907","url":null,"abstract":"Sophisticated mobile computing, sensing and recording devices are commonplace. Smart phones have achieved significant penetration and novel devices like Google Glass are imminent. These devices can serve most functions of a conventional notebook computer, but also have a range of additional capabilities, including image/audio/video recording, GPS location, compass, accelerometer, nearrange radio (NFC and Bluetooth), and soon health and fitness monitors. Moreover, these devices are carried by their users virtually around the clock, blurring the distinction between the online and offline world and enabling transformative new applications and services. For instance, mobile apps can provide location and activity-sensitive services and information, in the case of Google Glass overlaid right onto a user’s field of view. They can record what the user does, sees and hears for future reference; and they can keep track of a user’s encounters with nearby users’ devices to enable communication related to a shared experience or event. However, these applications and services also introduce a range of new threats to users’ privacy. While a user carries it, a mobile device can capture a complete record of the user’s location, online and offline activities, and social encounters, potentially including an audio-visual record. While such a record is very useful to a user for their own reference and to enable new applications, it is also highly sensitive and inherently private. Unlike information users post on Facebook or Twitter, most users would likely not want to share such a comprehensive record with anyone. In this paper, we catalog privacy threats introduced by these devices and applications. Our survey of threats underlines how privacy threats from mobile devices are fundamentally different and inherently more dangerous than in prior systems. For each specific risk vector, we describe technical challenges that, if solved, can mitigate its effects. We note that technical innovations merely provide a starting point: an end-to-end privacy-preserving infrastructure will require changes in how basic services are deployed, how laws","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80066686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ViFi: virtualizing WLAN using commodity hardware","authors":"Katherine Guo, Shruti Sanadhya, Thomas Y. C. Woo","doi":"10.1145/2645892.2645893","DOIUrl":"https://doi.org/10.1145/2645892.2645893","url":null,"abstract":"We consider an architecture in which the same WiFi infrastructure can be dynamically shared among multiple operators. Our system, ViFi, virtualizes WLAN resources, allowing for controlled sharing of both the uplink and downlink bandwidth. ViFi operates with stock 802.11 clients, and can be implemented entirely as a software add-on for commodity 802.11 APs.\u0000 ViFi puts users (customers) of different operators in separate groups, each creating a virtual WLAN. ViFi guarantees proportional fair share of channel access time at group level, and isolates traffic between groups. The key technical contribution of ViFi is a useful form of virtualization without requiring changes to the underlying WiFi protocol.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79765267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COAP: a software-defined approach for home WLAN management through an open API","authors":"Ashish Patro, Suman Banerjee","doi":"10.1145/2645892.2645902","DOIUrl":"https://doi.org/10.1145/2645892.2645902","url":null,"abstract":"In recent years, there has been a rapid growth in the adoption and usage of WiFi enabled networked devices at homes such as laptops, handheld device and wireless entertainment devices. In dense wireless deployments at homes, such as apartment buildings, neighboring home WLANs share the same unlicensed spectrum by deploying consumer-grade access points in their individual homes. In such environments, WiFi networks can suffer from intermittent performance issues such as wireless packet losses, interference from WiFi and non-WiFi sources due to the increasing diversity of devices that share the spectrum. In this paper, we propose a vendor- neutral cloud-based centralized framework called COAP to configure, co-ordinate and manage individual home APs using an open API implemented over the OpenFlow SDN framework.This paper describes the framework and motivates the potential benefits of the framework in home WLANs.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80609368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Timings matter: standard compliant ieee 802.11 channel access for a fully software-based SDR architecture","authors":"Bastian Bloessl, André Puschmann, C. Sommer, F. Dressler","doi":"10.1145/2643230.2643240","DOIUrl":"https://doi.org/10.1145/2643230.2643240","url":null,"abstract":"We present a solution for enabling standard compliant channel access for a fully software-based Software Defined Radio (SDR) architecture. With the availability of a GNU Radio implementation of an Orthogonal Frequency Division Multiplexing (OFDM) transceiver, there is substantial demand for standard compliant channel access. It has been shown that implementation of CSMA on a host PC is infeasible due to system-inherent delays. The common approach is to fully implement the protocol stack on the FPGA, which makes further updates or modifications to the protocols a complex and time consuming task. We take another approach and investigate the feasibility of a fully software-based solution and show that standard compliant broadcast transmissions are possible with marginal modifications of the FPGA. We envision the use of our system for example in the vehicular networking domain, where broadcast is the main communication paradigm. We show that our SDR solution exactly complies with the IEEE 802.11 Distributed Coordination Function (DCF) as well as Enhanced Distributed Channel Access (EDCA) timings. We were even able to identify shortcomings of commercial systems and prototypes.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85981195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"BeHop: a testbed for dense WiFi networks","authors":"Yiannis Yiakoumis, M. Bansal, Adam Covington, Johan van Reijendam, S. Katti, N. McKeown","doi":"10.1145/2643230.2643233","DOIUrl":"https://doi.org/10.1145/2643230.2643233","url":null,"abstract":"We present BeHop, a wireless testbed for dense WiFi networks often seen in residential and enterprise settings. BeHop aims to provide insights on the operation of dense deployments, and evaluate how different WiFi management strategies affect user experience and network behavior. It has sufficient flexibility to let us try different management techniques and setups (e.g. residential or enterprise, client or infrastructure-driven operation). It is deployed at a university dorm, where it acts as the main network for a diverse set of users and devices, exposing practical insights and implications on the operation of the network. In this paper we discuss the design and implementation of BeHop, and share our early experience over a five-month period.","PeriodicalId":43578,"journal":{"name":"Mobile Computing and Communications Review","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81810020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}