Search Word(s) in Title, Keywords, Authors, and Abstract: ns-2

A Study of Wireless Sensor Network Routing Protocols for Maintenance Access Hatch Condition Surveillance
Hoo-Rock Lee, Kyung-Yul Chung and Kyoung-Son Jhang
Page: 237~246, Vol. 9, No.2, 2013
10.3745/JIPS.2013.9.2.237
Keywords: Maintenance Hatch, Underground Facilities, WSN, Routing Protocol, ns-2
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Maintenance Access Hatches are used to ensure urban safety and aesthetics while facilitating the management of power lines, telecommunication lines, and gas pipes. Such facilities necessitate affordable and effective surveillance. In this paper, we propose a FiCHS (Fixed Cluster head centralized Hierarchical Static clustering) routing protocol that is suitable for underground maintenance hatches using WSN (Wireless Sensor Network) technology. FiCHS is compared with three other protocols, LEACH, LEACH-C, and a simplified LEACH, based on an ns-2 simulation. FiCHS was observed to exhibit the highest levels of power and data transfer efficiency.


A Network-Based Handover Scheme in HIP-Based Mobile Networks
Moneeb Gohar and Seok-Joo Koh
Page: 651~659, Vol. 9, No.4, 2013
10.3745/JIPS.2013.9.4.651
Keywords: HIP, network-based, handover, simulations
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In the Host Identity Protocol (HIP), the existing host-based handovr scheme tends to induce large handover delays and packet loss rates. To deal with this problem, we are proposing a network-based andover scheme for HIP in the mobile networks, in which the access routers of the mobile node will establish a handover tunnel and will perform the route optimization for data transmission. We also discuss how to extend the HIP Update message to use the proposed handover scheme. From ns-2 simulations, we can see that the proposed handover scheme can significantly reduce the handover delay and packet losses during handover, as compared to the existing handover schemes.


A Survey of QoS Based Routing Protocols for Wireless Sensor Networks
R.Sumathi and M.G.Srinivas
Page: 589~602, Vol. 8, No.4, 2012
10.3745/JIPS.2012.8.4.589
Keywords: Wireless Sensor Networks, Quality of Service, Reliability, Energy Efficiency, End-To-End Delay, Critical Data
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With the increasing demand for real time applications in the Wireless Senor Network (WSN), real time critical events anticipate an efficient quality-of-service (QoS) based routing for data delivery from the network infrastructure. Designing such QoS based routing protocol to meet the reliability and delay guarantee of critical events while preserving the energy efficiency is a challenging task. Considerable research has been focused on developing robust energy efficient QoS based routing protocols. In this paper, we present the state of the research by summarizing the work on QoS based routing protocols that has already been published and by highlighting the QoS issues that are being addressed. The performance comparison of QoS based routing protocols such as SAR, MMSPEED, MCMP, MCBR, and EQSR has also been analyzed using ns-2 for various parameters.


Partial Bicasting with Buffering for Proxy Mobile IPv6 Handover in Wireless Networks
Ji-In Kim and Seok-Joo Koh
Page: 627~634, Vol. 7, No.4, 2011
10.3745/JIPS.2011.7.4.627
Keywords: Proxy Mobile IPv6, Handover, Partial Bicasting, Buffering, Simulation Analysis
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This paper addresses the Proxy Mobile IPv6 (PMIP) handover using bicasting in mobile/wireless networks. The bicasting scheme can be used to support the PMIP handover, which tends to waste the network resources of wireless links and incurs data losses during handover. We propose an enhanced scheme of PMIP handover, called the partial bicasting with buffering for PMIP (PBB-PMIP). In the PBB-PMIP handover, the bicasting is performed in the “partial” region between the Local Mobility Anchor (LMA) and the Mobile Access Gateway (MAG), when a mobile node is in the handover area. The data packets are buffered at the new MAG during handover to reduce data losses and are then forwarded to mobile nodes after handover. By ns-2 simulations, the proposed PBB-PMIP scheme is compared with the existing schemes of PMIP and PMIP with bicasting. The proposed scheme can benefit from the reduction of handover delay and packet loss, and the effective use of the network resources of wireless links, as compared to the existing handover schemes.


Medium Access Control with Dynamic Frame Length in Wireless Sensor Networks
Dae-Suk Yoo and Seung Sik Choi
Page: 501~510, Vol. 6, No.4, 2010
10.3745/JIPS.2010.6.4.501
Keywords: Sensor Networks, Energy-Efficient MAC, S-MAC
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Wireless sensor networks consist of sensor nodes which are expected to be battery-powered and are hard to replace or recharge. Thus, reducing the energy consumption of sensor nodes is an important design consideration in wireless sensor networks. For the implementation of an energy-efficient MAC protocol, a Sensor-MAC based on the IEEE 802.11 protocol, which has energy efficient scheduling, has been proposed. In this paper, we propose a Dynamic S-MAC that adapts dynamically to the network-traffic state. The dynamic S-MAC protocol improves the energy consumption of the S-MAC by changing the frame length according to the network-traffic state. Using an NS-2 Simulator, we compare the performance of the Dynamic S-MAC with that of the SMAC protocol.


Decision of Maximum Congestion Window Size for TCP Performance Improvement by Bandwidth and RTT Measurement in Wireless Multi-Hop Networks
In Huh, Jae Yong Lee and Byung Chul Kim
Page: 34~38, Vol. 2, No.1, 2006
None
Keywords: wireless multi-hop network, TCP, congestion window
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In the wireless network, TCP performs poorly because it was originally designed for wired networks and does not take into consideration wireless characteristics such as mobility, high-loss probability, and hidden-terminal problems. In particular, in the wireless multi-hop networks, a large congestion window increases the probability of contention and packet losses, and TCP performance is degraded severely as a result. So, it is necessary to limit the TCP congestion window size in order keep the probability of contention loss in the system to a minimum. In this paper, we propose a new scheme for determining the maximum congestion window size based on the measured bandwidth and Round-Trip-Time (RTT). Using ns-2 simulation, we show that the proposed scheme reduces the probability of packet contention and improves TCP performance.


TASL: A Traffic-Adapted Sleep/Listening MAC Protocol for Wireless Sensor Network
Yuan Yang, Fu Zhen, Tae-Seok Lee and Myong-Soon Park
Page: 39~43, Vol. 2, No.1, 2006
None
Keywords: Wireless Sensor Network, MAC protocol, traffic aware, sleep/wake mechanism
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In this paper, we proposed TASL-MAC, a medium-access control (MAC) protocol for wireless sensor networks. In wireless sensor networks, sensor nodes are usually deployed in a special environment, are assigned with long-term work, and are supported by a limited battery. As such, reducing the energy consumption becomes the primary concern with regard to wireless sensor networks. At the same time, reducing the latency in multi-hop data transmission is also very important. In the existing research, sensor nodes are expected to be switched to the sleep mode in order to reduce energy consumption. However, the existing proposals tended to assign the sensors with a fixed Sleep/Listening schedule, which causes unnecessary idle listening problems and conspicuous transmission latency due to the diversity of the traffic-load in the network. TASL-MAC is designed to dynamically adjust the duty listening time based on traffic load. This protocol enables the node with a proper data transfer rate to satisfy the application¡¯s requirements. Meanwhile, it can lead to much greater power efficiency by prolonging the nodes¡¯ sleeping time when the traffic load of the network decreases. We evaluate our implementation of TASL-MAC in NS-2. The evaluation result indicates that our proposal could explicitly reduce packet delivery latency, and that it could also significantly prolong the lifetime of the entire network when traffic is low.