Saving Energy in Mobile Devices for On-Demand Multimedia Streaming -- A Cross-Layer Approach

This paper proposes a novel energy-efficient multimedia delivery system called EStreamer. First, we study the relationship between buffer size at the client, burst-shaped TCP-based multimedia traffic, and energy consumption of wireless network interfaces in smartphones. Based on the study, we design and implement EStreamer for constant bit rate and rate-adaptive streaming. EStreamer can improve battery lifetime by 3x, 1.5x and 2x while streaming over Wi-Fi, 3G and 4G respectively.Comment: Accepted in ACM Transactions on Multimedia Computing, Communications and Applications (ACM TOMCCAP), November 201

Power Saving Techniques in 5G Technology for Multiple-Beam Communications

The evolution of mobile technology and computation systems enables User Equipment (UE) to manage tremendous amounts of data transmission. As a result of current 5G technology, several types of wireless traffic in millimeter wave bands can be transmitted at high data rates with ultra-reliable and small latency communications. The 5G networks rely on directional beamforming and mmWave uses to overcome propagation and losses during penetration. To align the best beam pairs and achieve high data rates, beam-search operations are used in 5G. This combined with multibeam reception and high-order modulation techniques deteriorates the battery power of the UE. In the previous 4G radio mobile system, Discontinuous Reception (DRX) techniques were successfully used to save energy. To reduce the energy consumption and latency of multiple-beam 5G radio communications, we will propose in this paper the DRX Beam Measurement technique (DRX-BM). Based on the power-saving factor analysis and the delayed response, we will model DRX-BM into a semi-Markov process to reduce the tracking time. Simulations in MATLAB are used to assess the effectiveness of the proposed model and avoid unnecessary time spent on beam search. Furthermore, the simulation indicates that our proposed technique makes an improvement and saves 14% on energy with a minimum delay

A comprehensive simulation analysis of LTE Discontinuous Reception (DRX)

In 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

Energy Efficiency in Communications and Networks

The topic of "Energy Efficiency in Communications and Networks" attracts growing attention due to economical and environmental reasons. The amount of power consumed by information and communication technologies (ICT) is rapidly increasing, as well as the energy bill of service providers. According to a number of studies, ICT alone is responsible for a percentage which varies from 2% to 10% of the world power consumption. Thus, driving rising cost and sustainability concerns about the energy footprint of the IT infrastructure. Energy-efficiency is an aspect that until recently was only considered for battery driven devices. Today we see energy-efficiency becoming a pervasive issue that will need to be considered in all technology areas from device technology to systems management. This book is seeking to provide a compilation of novel research contributions on hardware design, architectures, protocols and algorithms that will improve the energy efficiency of communication devices and networks and lead to a more energy proportional technology infrastructure

Performance Evaluation of Power Efficient Mechanisms on Multimedia over LTE-A Networks

Power optimization is a critical challenge in multimedia services over cellular communication systems. Long Term Evolution-Advanced (LTE-A) has been developed for higher bandwidth access for accommodating today’s heavy data applications to provide better performance. Idle mode permits cellularstations to manipulate power and sources with the aid of limiting its activity for discrete periods and this eliminates the lively requirement for handover and other ordinary operations. Also, provides a periodical method for the cell station for pending downlink traffic directed to the cellularstation and as a result gets rid network handover traffic from basically inactive cellular stations. Discontinuous Reception (DRX) has been carried out to decrease the power intake of the consumer device, and transmission of big quantity of data. At data transfer, mobile device and the network phases negotiation occur. During other times, the device turns its receiver off and enters a low power state. Thereby similarly assisting numerous services and big quantities of information transmissions. This study prepossession of a massive quantity of data. Also proposes the two-power optimization modes idle mode and DRX mode parameters to achieve maximum possible power saving with the higher quality of multimedia services. Furthermore, the effectiveness of using DRX short cycles and DRX long cycles on multimedia services and the overall performance. Using OPNET Simulator 17.5, it concluded that DRX mechanism is preferred to operate compared with the Idle mechanism, also resulted that the DRX long cycles are a very good choice for all multimedia services and the overall network performance

Energy efficiency in short and wide-area IoT technologies—A survey

In the last years, the Internet of Things (IoT) has emerged as a key application context in the design and evolution of technologies in the transition toward a 5G ecosystem. More and more IoT technologies have entered the market and represent important enablers in the deployment of networks of interconnected devices. As network and spatial device densities grow, energy efficiency and consumption are becoming an important aspect in analyzing the performance and suitability of different technologies. In this framework, this survey presents an extensive review of IoT technologies, including both Low-Power Short-Area Networks (LPSANs) and Low-Power Wide-Area Networks (LPWANs), from the perspective of energy efficiency and power consumption. Existing consumption models and energy efficiency mechanisms are categorized, analyzed and discussed, in order to highlight the main trends proposed in literature and standards toward achieving energy-efficient IoT networks. Current limitations and open challenges are also discussed, aiming at highlighting new possible research directions

On feasibility of the UE power saving signal for the 5G new radio

Abstract. The objective of this thesis is to study and evaluate physical layer signals and channels to achieve the user equipment (UE) power saving in the 3rd generation partnership project (3GPP) new radio (NR). The fifth generation (5G) mobile network has strict objectives regarding power consumption and performance. The UE power consumption also has a big impact on the end user’s quality of experience (QoE) and future deployment of NR devices. Therefore, it is very important to study ways to reduce UE power consumption. One feasible power saving technique is the usage of so-called power saving signal or channel, which triggers the UE to transition to the active mode from the power saving mode. The first part of this work provides an overview of general properties of the NR and its physical downlink signals and channels, as well as the UE operation and power consumption in the connected mode. Then, examples of existing power saving techniques are discussed and a new scheme of the wake-up mechanism and the UE power saving signal/wake-up signal (WUS) is described. Lastly, different design options for the power saving signal are described and their detection performance is studied. The power saving signal options of this thesis can be divided into physical downlink control channel (PDCCH) based and sequence-based signals/channels. In the PDCCH based option, the power saving indication is carried as a payload of the PDCCH. Studied sequence-based options are the secondary synchronization signal (SSS), the PDCCH demodulation reference signal (DMRS), the channel state information reference signal (CSI-RS) and a UE-specific sequence that is mapped to all radio resources allocated for the PDCCH. The detection of the latter is done in time domain, and the detection of the other sequences is done in frequency domain. The detection performance of these signals/channels is compared based on link-level simulation results. Simulations were done with a Matlab-based simulator. They show the impact of the frequency- and time-selectivity and implementation impairments. Based on the numerical results, the impact of the UE speed up to 120 km/h and the carrier frequency offset (CFO) up to 400 Hz can be neglected with all the options except CSI-RS. It was shown that the sequence-based WUS options tend to suffer from the frequency-selective radio channel. By making decisions within the channel’s coherence bandwidth and using precoder cycling, the negative impact of the channel can be reduced. With these techniques, PDCCH DMRS outperforms all the other sequence-based options. However, in terms of detection performance, the PDCCH based power saving signal/channel is the most robust option of this set of candidates.Päätelaitteen virransäästösignaalin soveltuvuus 5G:n uuteen radiorajapintaan. Tiivistelmä. Tämän diplomityön tavoitteena on tutkia ja verrata fyysisen kerroksen signaaleja, päätelaitteen (user equipment, UE) virransäästön toteuttamiseksi 3GPP:n uudessa radiorajapinnassa (New Radio, NR). Viidennen sukupolven (5th generation, 5G) mobiiliverkolla on tiukat tavoitteet virransäästön ja suorituskyvyn osalta. Päätelaitteen virrankulutuksella on myös suuri vaikutus loppukäyttäjän kokemukseen ja tulevien NR-laitteiden käyttöönottoon. Siksi onkin erittäin tärkeää tutkia mahdollisia tapoja vähentää päätelaitteen virrankulutusta. Yksi mahdollinen virransäästötekniikka on niin sanottu virransäästösignaali, joka herättää päätelaitteen virransäästötilasta verkkoyhteyteen. Työn ensimmäinen osa käsittelee NR:n yleisiä ominaisuuksia, alalinkin fyysisiä signaaleja ja kanavia, sekä päätelaitteen virrankulutusta verkkoyhteydessä. Seuraavaksi käsitellään olemassa olevia virransäästötekniikoita, sekä käydään läpi uutta herätys-tyyppistä mekanismia ja päätelaitteen virransäästösignaalin/herätyssignaalin (wake-up signal, WUS) toimintaa. Lopuksi kuvataan erilaisia virransäästösignaalivaihtoehtoja ja tutkitaan niiden havaitsemisen suorituskykyä. Työn virransäästösignaalivaihtoehdot voidaan jakaa alalinkin kontrollikanava- (physical downlink control channel, PDCCH) ja sekvenssipohjaisiin signaaleihin/kanaviin. PDCCH-pohjaisessa vaihtoehdossa virransäästösignaali siirretään PDCCH:n hyötykuormana. Tutkitut sekvenssipohjaiset vaihtoehdot ovat toissijainen synkronointisignaali (secondary synchronization signal, SSS), PDCCH-demodulaatio-referenssisignaali (demodulation reference signal, DMRS), kanavan tilatieto-referenssisignaali (channel-state information reference signal, CSI-RS), sekä UE-spesifinen sekvenssi, joka asetetaan PDCCH:n jokaiseen alikantoaaltoon. Jälkimmäisen havaitseminen tehdään aikatasossa ja muiden sekvenssien havaitseminen tehdään taajuustasossa. Näiden signaalien/kanavien havaitsemisen suorituskykyä vertaillaan linkkitason simulointitulosten perusteella. Simulaatiot tehtiin Matlab-pohjaisella simulaattorilla. Ne esittävät aika- ja taajuusselektiivisyyden, sekä toteutuksen epäideaalisuuksien vaikutusta. Numeeristen tulosten perusteella, UE:n nopeus arvoon 120 km/h ja kantoaaltotaajuussiirto (carrier frequency offset, CFO) 400 Hz:iin asti voidaan jättää huomioimatta, kaikkien muiden paitsi CSI-RS:n tapauksessa. Työssä osoitettiin, että sekvenssipohjaiset WUS-vaihtoehdot kärsivät taajuusselektiivisestä radiokanavasta. Kanavan negatiivista vaikutusta voidaan pienentää tekemällä päätöksiä kanavan koherenssikaistanleveyttä pienemmissä osissa, sekä käyttämällä syklistä esikooderia. Näillä tekniikoilla PDCCH DMRS suoriutuu kaikkia muita sekvenssipohjaisia vaihtoehtoja paremmin. Kuitenkin, havaitsemisen suorituskyvyn perusteella PDCCH-pohjainen virransäästösignaali/kanava on vahvin ehdokas näistä vaihtoehdoista

System-level analysis of the tradeoffs between power saving and capacity/QoS with DRX in LTE

In 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