VoIP over WLAN: voice capacity, admission control, QoS, and MAC

Next generation mobile networks aim to provide faster speed and more capacity along with energy efficiency to support video streaming and massive data sharing in social and communication networks. In these networks, user equipment has to register with IP Multimedia Subsystem (IMS) which promises quality of service to the mobile users that frequently move across different access networks. After each handover caused due to mobility, IMS provides IPSec Security Association establishment and authentication phases. The main issue is that unnecessary reregistration after every handover results in latency and communication overhead. To tackle these issues, this paper presents a lightweight Fast IMS Mobility (FIM) registration scheme that avoids unnecessary conventional registration phases such as security associations, authentication, and authorization. FIM maintains a flag to avoid deregistration and sends a subsequent message to provide necessary parameters to IMS servers after mobility. It also handles the change of IP address for user equipment and transferring the security associations from old to new servers. We have validated the performance of FIM by developing a testbed consisting of IMS servers and user equipment. The experimental results demonstrate the performance supremacy of FIM. It reduces media disruption time, number of messages, and packet loss up to 67%, 100%, and 61%, respectively, as compared to preliminaries.

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“…We have set = 50 pkts/sec as used by [31]. On a constant handover delay, we have measured loss of packets for IMS, MIP-IMS, and FIM.…”

Section: Packet Lossmentioning

confidence: 99%

Handover Based IMS Registration Scheme for Next Generation Mobile Networks

Tahira

Sher

Ullah

et al. 2017

Wireless Communications and Mobile Computing

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“…In this paper, we assume that D Req of AF frames is 25 ms (i.e. maximum delay to attain an acceptable quality for voice over Internet Protocol in a local area network [25]). …”

Section: Performance Evaluationmentioning

confidence: 99%

Early Wake-Up Decision Algorithm for ONUs in TDM-PONs With Sleep Mode

Mohammed

Newaz

Uddin

et al. 2016

J. Opt. Commun. Netw.

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Abstract-Recent IEEE and ITU-T standards for TDM-Passive Optical Network (TDM-PON) with sleep mode recommend that the Optical Line Terminal (OLT) in a TDM-PON should be in charge of invoking an Optical Network Units (ONU) to move into sleep state in absence of frames. It is considered that, on upstream frame arrival, a sleeping ONU can leave sleep state, in which an ONU turns off its transmitter or both transmitter and receiver immediately, prior to its assigned sleep interval length. In this paper, we refer to this approach as immediate early wakeup (IMEW). According to the standards, the OLT may or may not allow an ONU to trigger early wake-up function (EWF) on upstream frames arrival. If the OLT does not allow EWF (not support early wake-up (NSEW)), an ONU should stay in sleep state during its assigned sleep duration and buffer all the upstream frames while it is in this state. In IMEW, upstream frames experience small delay but ONU's energy consumption increases remarkably. Conversely, in NSEW, an ONU consumes less energy compared to IMEW at the price of increasing upstream frame delay and possibility of its buffer overflow. In this paper, the limitations of IMEW and NSEW have motivated us to propose a novel Early Wake-up Decision (EWuD) algorithm which aims at meeting upstream frame delay requirement while reducing ONUs' energy consumption as much as possible. The role of EWuD algorithm is to select an appropriate time for triggering EWF taking into consideration two factors: (1) buffer overflow probability and (2) delay requirement violation of upstream frames. We evaluate EWuD performances using our TDM-PON OPNET Modular based simulation model under wide range of scenarios. Findings demonstrate that our proposed EWuD can successfully meet delay requirement of all upstream frames while reducing ONU's energy consumption significantly.

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“…Both the LEAP and the adaptive polling scheme poll the stations in the active list one-by-one resulting in significant operation overhead. While isochronous coordination function (ICF) (Lam et al, 2006) reduces this overhead by finding a way to poll multiple stations at a time and providing a dynamic TDMA-like service for transporting voice packets efficiently (Cai et al, 2006a(Cai et al, , 2006bLi and Xiao, 2006;Li et al, 2008). In polling list-based schemes, it is difficult to accurately determine which list a station should belong to with little overhead, and once an active station is added in an inactive polling list, the real-time performance cannot be guaranteed, and this may cause serious problems in industrial environment.…”

Section: Polling Protocols In Wireless Networkmentioning

confidence: 99%

Polling in the frequency domain: a new MAC protocol for industrial wireless network for factory automation

Lin

Liang

Huang

et al. 2015

IJAHUC

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Wireless technologies are becoming more and more attractive for industrial communication. In the field of factory automation, the high communication requirements in terms of predictability, reliability and real-time make the adoption of wireless technologies challenging, due to the inefficiency of the wireless physical layer and deterministic medium access control (MAC) protocols. In this paper, a frequency domain polling MAC protocol (FDP-MAC) is proposed, which takes advantage of the orthogonal frequency-division multiplexing (OFDM) technology to achieve simultaneously polling. In the FDP-MAC, a dynamic time division multiple access (TDMA) scheduling and a downlink acknowledgements aggregation method are also presented to improve the communication efficiency further. We validate the effectiveness of FDP-MAC through simulations, and results indicate that FDP-MAC can meet typical factory automation applications' communication requirements.

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VoIP over WLAN: voice capacity, admission control, QoS, and MAC

Cited by 54 publications

References 50 publications

Handover Based IMS Registration Scheme for Next Generation Mobile Networks

Handover Based IMS Registration Scheme for Next Generation Mobile Networks

Early Wake-Up Decision Algorithm for ONUs in TDM-PONs With Sleep Mode

Polling in the frequency domain: a new MAC protocol for industrial wireless network for factory automation

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