Are you the publisher? Claim or contact us about this channel


Embed this content in your HTML

Search

Report adult content:

click to rate:

Account: (login)

More Channels


Channel Catalog


older | 1 | 2 | 3 | (Page 4)

    0 0

    Web browsing optimization over 2.5G and 3G: end-to-end mechanisms vs. usage of performance enhancing proxies Gómez Montenegro, Carlos; Catalán Cid, María Luisa; Viamonte Solé, David; Paradells Aspas, Josep; Calveras Augé, Anna M. 2.5 Generation (2.5G) and Third Generation (3G) cellular wireless networks allow mobile Internet access withbearers specifically designed for data communications. However, Internet protocols under-utilize wireless widearea network (WWAN) link resources, mainly due to large round trip times (RTTs) and request–reply protocolpatterns. Web browsing is a popular service that suffers significant performance degradation over 2.5G and 3G. Inthis paper, we review and compare the two main approaches for improving web browsing performance over wirelesslinks: (i) using adequate end-to-end parameters and mechanisms and (ii) interposing a performance enhancingproxy (PEP) between the wireless and wired parts. We conclude that PEPs are currently the only feasible way forsignificantly optimizing web browsing behavior over 2.5G and 3G. In addition, we evaluate the two main currentcommercial PEPs over live general packet radio service (GPRS) and universal mobile telecommunications system(UMTS) networks. The results show that PEPs can lead to near-ideal web browsing performance in certain scenarios. Published version on Wiley's platform: https://onlinelibrary.wiley.com/doi/abs/10.1002/wcm.456

    0 0

    Benefits of using mobile ad-hoc network protocols in federated satellite systems for polar satellite missions Ruiz de Azúa Ortega, Joan Adrià; Camps Carmona, Adriano José; Calveras Augé, Anna M. The Operational Network of Individual Observation Nodes (ONION) project evaluated the benefits of applying Distributed Satellite System (DSS) architectures to Earth Observation. One of its outcomes is the identification of Arctic services as top priority current user needs that require near-realtime observations. Using Inter-Satellite Communications (ISC) capabilities, a Federated Satellite System (FSS) can establish a win-win collaboration between two spacecrafts to provide these services. However, as a FSS is established during the contact between two satellites, the service duration is limited. Therefore, the Internet of Satellites (IoSat) paradigm promotes the use of multi-hop sporadic networks to deploy FSS. In this context, the routing protocol (which identifies routes between a source-destination pair) becomes crucial. One of the most extended networks is the Mobile Ad-hoc Network (MANET), in which nodes are constantly moving and changing the network topology. In principle, applying MANET technologies in the IoSat context would provide self-organization, self-configuration, and flexibility to satellite systems. The Optimized Link-State Routing (OLSR) protocol is the predominant solution in MANET, because it quickly reacts against topology changes. This article aims at studying the benefits of using satellite networks with MANET solutions (e.g. OLSR) for polar satellite missions. The results presented in this article demonstrate that the access time is significantly improved, and thus these new Arctic services can be achieved. © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

    0 0

    Softwarized LTE self-backhauling solution and its evaluation Gamboa Jimenez, Gonzalo; Seyfettin Demirkol, Ilker Long Term Evolution (LTE) is projected to be the mostly used mobile technology before 2020, thanks to the high data rates, all IP-based and simplified architecture it brings compared to previous mobile network technologies. To address the exponential data requirements of the future, a targeted solution for LTE is network densification, i.e., deploying small cells (cells with reduced radius compared to macro cells), which will enable better frequency reuse. However, a challenge here is the backhauling of the evolved-NodeBs (eNBs) used for small cells, since the fiber-based backhauling is costly and is not always feasible given the physical environment. For this, a recent idea is to use LTE self-backhauling, where an eNB can relay its data to another eNB through the use of LTE technology. In this paper, we develop and evaluate an implementation of LTE Self-Backhauling building on an open-source software and commodity hardware (specifically, regular PCs and low-cost software-defined radios) for the LTE system. For this, we implement a self-backhauled eNodeB, which connects to another eNB through an LTE connection. Through physical experimentation using off-the-shelf user equipments (UEs), we show that the method proposed is viable and can improve the network coverage and the throughput of the network.

    0 0

    Software-based implementation of LTE/Wi-Fi aggregation and its impact on higher layer protocols Ibarra Gómez, David; Desai, Nitin Pradeep; Seyfettin Demirkol, Ilker Due to the fast growing of data consumed in mobile devices through cellular networks, solutions that provide higher data rates are an important target for the mobile networking community. One such solution is the aggregation of mobile technologies (most commonly LTE) with wireless LAN solutions (most commonly Wi-Fi). Seeing its potential impact, 3GPP has devised the LTE/Wi-Fi Aggregation (LWA) specification, which defines a tight coupling between eNBs and Wi-Fi Access Points (APs). In this paper, we implement and evaluate an LWA solution, and compare its performance to the one for full offloading (only Wi-Fi) and no offloading (only LTE) through physical experimentation. The developed prototype LWA solution is based on open source and commodity hardware, which promises a low-cost and easily implementable LWA solution. Aggregation and offloading process are managed by the eNB, therefore, the core network remains intact without any modification. Physical experiments are done to detail the network performances for all these three policies for TCP and UDP traffic and both for uplink and downlink connections. In TCP transmissions with LWA policy, the different delays between Wi-Fi and LTE links causes the performance degradation because of the out-of-order arrivals of the segments. For this, we evaluate a solution where an artificial delay is added to reduce the number of out-of-order packets. ©2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

    0 0

    Modeling the connectivity of Data-Channel-based Bluetooth Low Energy mesh networks Darroudi, Seyed Mahdi; Gómez Montenegro, Carlos Bluetooth Low Energy (BLE) has become one of the most popular low-power wireless technologies. While BLE was originally designed for star topology networks only, recent developments have focused on enabling mesh network topology support for BLE. An emerging category of BLE mesh network initiatives is based on routing data units over BLE data channels. This letter investigates the fundamental connectivity parameters of data-channel-based BLE mesh networks, such as the probability of no isolation of a node and network K-connectivity. We provide an analytical model for both parameters which is validated by means of extensive simulations. © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

    0 0

    Transmitter localization in vessel-like diffusive channels using ring-shaped molecular receivers Turan, Meriç; Akdeniz, Bayram Cevdet; Kuran, Mehmet Sükrü; Yilmaz, Hüseyin Birkan; Seyfettin Demirkol, Ilker; Pusane, Ali Emre; Tugcu, Tuna Molecular communication via diffusion in vessellike environment targets critical applications such as detection of abnormal and unhealthy cells. In this work, we derive the analytical formulation of the channel model for diffusion dominated movement, considering ring-shaped (i.e., patch) observing receivers and Poiseuille flow with the aim of localization of the transmitter cell. Then, we derive formulations using this channel model for two different application scenarios. We assume that the emission start time is known in the first scenario, and unknown in the second one. We successfully localize the transmitter cell using a single receiver for the first scenario, whereas two receivers are used to localize the transmitter cell in the second scenario. Lastly, the devised analytical framework is validated with simulations. © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

older | 1 | 2 | 3 | (Page 4)