Browsing by Author "Koudouridis, G. P."

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  • Handover Performance and Power Consumption Analysis of LTE Mobile Relays
    (2020-11) Tayyab, Muhammad; Koudouridis, G. P.; Gelabert, X.; Jantti, R.
     A4 Artikkeli konferenssijulkaisussa
    Mobile relay node (MRN) is one of the cheaper options for reliable communication when users are moving by public transport (i.e. bus, tram, train, subway, etc.), especially in urban areas. Critically, MRNs need to maintain a backhaul connection with the fixed infrastructure via a donor eNB, (DeNB). If the MRN fails to successfully handover (HO) from one DeNB to another, it will create a single point of failure, i.e. the connection of all UEs connected to MRN will be dropped. In this paper, we address the HO performance of a MRN including a power consumption analysis thereof. We investigate the potential gains in terms of HO rate, HO failure ratio (HOFR), ping-pong (PP) rate and power consumption (both at UE and eNB) when a MRN is deployed on a bus traveling along the cell edges of surrounding macro BSs. We also look over the MRN HO failure cases to identify the causes of HO failures that are more critical for the UEs onboard. Numerical results indicate that deploying a MRN on the roof-top of a bus improves the HO rates 15%, HOFR 8%, PP rate 17%, UE power consumption 21%, and eNB power consumption 14% on average for all simulated cases. We have also established that UL transmission errors are the most dominant causes of turning MRN to a single point of failure during a HO.
  • Receiver Power Consumption during Handover in LTE
    (2019) Tayyab, Muhammad; Koudouridis, G. P.; Gelaberr, X.; Jäntti, Riku
     A4 Artikkeli konferenssijulkaisussa
    Recently, handover (HO) has gathered huge interest as the cellular mobile users desire for better quality of service (QoS) and continuous connection has increased. The power consumption is increasing day by day due to growing data rate demands of the users that directly impacts operators' operational expenditures (OPEX) and, not least, the environment by increased CO2 emissions. In this paper, we address the power consumption caused by the air-interface signaling messages received at both the eNB and User Equipment (UE) during HO in a Long Term Evolution (LTE) cellular network. A receiver power consumption model is presented with a detailed quantitative analysis using system level simulations. Numerical results indicate that the largest contributor to received air-interface HO signaling overhead is the reception of the measurement report by the eNB.
  • Signaling Overhead and Power Consumption during Handover in LTE
    (2019-04-01) Tayyab, M.; Koudouridis, G. P.; Gelabert, X.; Jantti, R.
     A4 Artikkeli konferenssijulkaisussa
    In this paper, we address the signaling overhead and the power consumption that results from the transmission of handover-related signaling in a Long Term Evolution (LTE) cellular network. Specifically, we analyze the contribution of the different signaling messages over the air-interface, and their impact on power consumption both at the eNB and at the User Equipment (UE) during handover (HO). A quantitative analysis is provided using system level simulations. We observe that, within the HO process, the largest contributor to air-interface signaling overhead is the transmission of the measurement report by the UE. This uplink (UL) transmission suffers from different channel impairments, due to interference and transmission range, for particular cell sizes. As a consequence, uplink signaling retransmissions are triggered causing higher signaling load and consequently higher power consumption, this being especially detrimental to battery-powered devices.
  • Uplink Reference Signal Based Handover with Mobile Relay Node Assisted User Clustering
    (2020-12) Tayyab, Muhammad; Koudouridis, G. P.; Gelabert, X.; Jantti, R.
     A4 Artikkeli konferenssijulkaisussa
    In today's cellular networks, an increasing number of connected devices on-board in fast-moving vehicles would require more efficient handover (HO) procedures. To this end, we investigate the utilization of mobile relay nodes (MRNs) in vehicles to facilitate efficient HO and HO-related power consumption reductions for all on-board user equipments (UEs). In particular, the potential gains in terms of HO rate, HO failure ratio (HOFR), ping-pong (PP) rate, and total power consumption are studied for different UE cluster sizes. To eliminate the measurement power-consuming procedure, uplink (UL) reference signals (RS) transmitted by UEs are exploited. Four different case scenarios are simulated utilizing both the DL and UL RS based HO procedure, with and without deploying MRNs on the buses traveling along the cell edges of surrounding macro BSs. Simulation results indicate that the UL RS based HO procedure can improve HO performance significantly because it reduces the air-interface signaling messages, namely the measurement report (MeasReport) transmission and reception. Also, in terms of power consumption, deploying MRNs is a more attractive solution with substantial power reduction for onboard UEs of higher cluster size.