1,721,074 research outputs found
System-level analysis of the tradeoffs between power saving and capacity/QoS with DRX in LTE
Full text linkIn an LTE cell, Discontinuous Reception (DRX) allows the central base station to configure User Equipment for periodic wake/sleep cycles, so as to save energy. Several parameters are associated to DRX operations, thus allowing for optimal performance with different traffic profiles (i.e., CBR-like, bursty, periodic arrivals of variable-sized packets, etc.). This work investigates how to configure these parameters and explores the tradeoff between power saving, on one side, and per-user QoS and cell capacity, on the other. Unlike previous work, mostly based on analytical models neglecting key aspects of LTE, our evaluation is carried out using a fully-fledged packet simulator. This allows us to discover previously unknown relationships and to propose configuration guidelines for operators
A comprehensive simulation analysis of LTE Discontinuous Reception (DRX)
Full text linkIn an LTE cell, Discontinuous Reception (DRX) allows
the central base station to configure User Equipments for
periodic wake/sleep cycles, so as to save energy. DRX operations
depend on several parameters, which can be tuned to achieve optimal
performance with different traffic profiles (i.e., CBR vs.
bursty, periodic vs. sporadic, etc.). This work investigates how to
configure these parameters and explores the trade-off between
power saving, on one side, and per-user QoS, on the other. Unlike
previous work, chiefly based on analytical models neglecting key
aspects of LTE, our evaluation is carried out via simulation. We
use a fully-fledged packet simulator, which includes models of all
the protocol stack, the applications and the relevant QoS metrics,
and employ factorial analysis to assess the impact of the many
simulation factors in a statistically rigorous way. This allows us
to analyze a wider spectrum of scenarios, assessing the interplay
of the LTE mechanisms and DRX, and to derive configuration
guidelines
Resource allocation for network-controlled device-to-device communications in LTE-Advanced
Full text linkNetwork-controlled device-to-device (D2D) communication allows cellular users to communicate directly, i.e., without passing through the eNodeB, while the latter retains control over resource allocation. This allows the same time–frequency resources to be allocated to spatially separated D2D flows simultaneously, thus increasing the cell throughput. This paper presents a framework for: (1) selecting which communications should use the D2D mode, and when, and (2) allocating resources to D2D and non-D2D users, exploiting reuse for the former. We show that the two problems, although apparently similar, should be kept separate and solved at different timescales in order to avoid problems, such as excessive packet loss. We model both as optimization problems, and propose a heuristic solution to the second, which must be solved at millisecond timescales. Simulation results show that our framework is practically viable, it avoids the problem of packet losses, increases throughput and reduces delays
SAPIENT-Simulator Modelling and Architecture
Full text linkFuture aeronautical communications will be based on the TCP/IP protocol stack, and will occur through a number of different data-link channels (e.g., satellite, terrestrial), with multipath capabilities – the so-called multilink. Seamless vertical handover between different data-links is a requirement and it will improve the safety and reliability of AEROCOM systems, possibly enabling remote-piloted aircrafts (RPAs) for civil operations. This paper describes the modelling, design and implementation of an AEROCOM system simulator based on OMNeT++, developed in the framework of the SAPIENT EU project. The simulator includes models of the aircrafts, including their mobility, terrestrial and satellite data links and core network. Moreover, it includes a solution to simulate the effect of multilink capabilities, which enables one to test multilink decision policies
Method for managing data transmission power in mobile cellular networks
No full textA method manages sub-frame data transmission in a cellular network including a macro node and at least one small node associated therewith. The method includes at a macro node side: based on channel quality information from user equipment associated with the macro node, grouping the user equipment into a first group that can be served at a macro node first transmission power and a second group that has to be served at a macro node second transmission power higher than the macro node first transmission power, and determining a sub-frames pattern including: a number of no-transmission sub-frames wherein data transmission is prevented at the macro node side, a number of limited-transmission sub-frames wherein data transmission is allowed at the macro node side at only the first transmission power, and a number of normal-transmission sub frames wherein data transmission is allowed at the macro node side at the second transmission power
Ensuring Lossless Workload Migration at the Edge with SRv6
No full textIn the context of edge computing, service migration between servers may be needed, for example, to support end user mobility or for load balancing purposes. In this work, we propose a novel solution for service continuity in the presence of workload migration at the edge, which leverages Segment Routing (SR) over IPv6 (SRv6) for packet steering, Software Defined Networking (SDN) and the P4 language for network configuration and programmability, and Network Function Virtualization (NFV) for buffering packets during workload migration. We evaluate our approach on a testbed wherein we use ONOS as SDN controller, and exploit Mininet to emulate the core network of P4 BMv2 switches. We analyze the performance of our SRv6 solution against a non-SRv6 alternative that uses IPv6 routing mechanism. Results highlight the scalability and flexibility of the proposed solution compared to the state of the art
Method for scheduling radio resources
No full textA method for allocating resource blocks of a transmission frame on a cellular network. The cellular network includes a cluster of antennas and a master unit of the cluster. Each antenna of each cluster is configured to provide radio coverage over a corresponding cell to exchange data with corresponding user equipment in communication with the antenna. During the transmission frame the antennas of the cluster are configured to be selectively activated and muted according to a plurality of cluster muting conditions
Method and System for data tunneling in device to device communications assisted by a telecommunication network
No full textA method for managing data packets transmitted by a first user equipment to be received by a second user equipment through a radio network includes having the radio network comprising a radio transceiver station receive data packets transmitted by the first user equipment. For each data packet received, checking whether the data packet comprises a request for a data packet tunneling. For each data packet comprising a request for data packet tunneling, providing the data packet to a relay protocol entity at a Radio Link Control protocol layer. The relay protocol entity is configured for generating at least one tunneling data packet, said generating at least one tunneling data packet comprises inserting at least a portion of the transmitted data packet into the at least one tunneling data packet and transmitting the tunneling data packet to the second user equipment
Simulating Cellular Communications in Vehicular Networks: Making SimuLTE Interoperable with Veins
Full text linkThe evolution of cellular technologies toward 5G progressively enables
efficient and ubiquitous communications in an increasing number of fields.
Among these, vehicular networks are being considered as one of the most
promising and challenging applications, requiring support for communications in
high-speed mobility and delay-constrained information exchange in proximity. In
this context, simulation frameworks under the OMNeT++ umbrella are already
available: SimuLTE and Veins for cellular and vehicular systems, respectively.
In this paper, we describe the modifications that make SimuLTE interoperable
with Veins and INET, which leverage the OMNeT++ paradigm, and allow us to
achieve our goal without any modification to either of the latter two. We
discuss the limitations of the previous solution, namely VeinsLTE, which
integrates all three in a single framework, thus preventing independent
evolution and upgrades of each building block
Server-side QUIC connection migration to support microservice deployment at the edge
Full text linkIn edge computing environments, microservices are typically deployed in the form of containers. To maintain proximity between edge computing services and mobile users, containers need to be migrated between nodes. When migrating containers, however, it is important to consider that they typically have ongoing communications with client endpoints. Moreover, in case of connection-oriented protocols, communicating endpoints share a state (i.e., the connection), which needs to be migrated as well. Connection-oriented protocols like TCP were not designed having connection migration in mind, thus their connections cannot survive a change of IP address or port number. On the other hand, QUIC, a transport protocol recently standardised by IETF, provides a mechanism for client-side connection migration, whereas a server-side connection migration is not yet implemented nor investigated. In this work, we propose an extension of QUIC to support server-side connection migration when a container is migrated between servers. We designed three different strategies, fitting a diverse set of scenarios, wherein the migration procedure is either or not supported by a centralised entity, e.g., an orchestrator. We implemented and verified the proposed extension. Besides, we evaluated it on a real testbed, showing how each of the three strategies is impacted by different container migration techniques and container sizes. To conclude, we compared our solution against two alternatives based on TCP+DNS and MPTCP respectively, demonstrating performance improvements in terms service-migration time
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