Anand S.V.R.

• Indian Institute of Science Bangalore

In this paper, we present a generic controller that ensures fair and efficient operation of IEEE 802.11 infrastructure wireless local area networks (WLANs) with multiple co-channel access points. Our controller addresses performance issues of long-lived TCP transfers in multi-AP WLANs, by overlaying a coarse time-slicing scheduler on top of a casca...

Real-time multimedia applications are often deployed to provide critical information in situations such as news coverage of an event or an incident or an ambulance rushing to provide emergency care. Mobile cellular coverage and performance of a provider network varies both spatially and temporally and challenges the ability of the network to suppor...

In this paper, we present a generic plug-and-play controller that ensures fair and efficient operation of IEEE~802.11 infrastructure wireless local area networks with multiple co-channel access points, without any change to hardware/firmware of the network devices. Our controller addresses performance issues of TCP transfers in multi-AP WLANs, by o...

We present design and implementation of CyPhyS+, a comprehensive, low-cost and standard complaint Cyber Physical System for remote health monitoring of elderly staying in old age homes. It is an end-to-end 6LoWPAN based healthcare system, which provides reliable and secured medical data acquisition, on the fly medical data analytics and visualizati...

Packets traversing through a multi-hop Low-power and Lossy Network (LLN) experience various link outage conditions in transit that can lead to packet loss at an intermediate relay node. Motivated by the problem of providing high Packet Delivery Ratio (PDR) in the LLNs running RPL(Routing Protocol for Low-power and Lossy Networks) routing protocol,...

We have developed SmartConnect, a tool that addresses the growing need for the design and deployment of multihop wireless relay networks for connecting sensors to a control center. Given the locations of the sensors, the traffic that each sensor generates, the quality of service (QoS) requirements, and the potential locations at which relays can be...

We are motivated by the problem of impromptu or as- you-go deployment of wireless sensor networks. As an application example, a person, starting from a sink node, walks along a forest trail, makes link quality measurements (with the previously placed nodes) at equally spaced locations, and deploys relays at some of these locations, so as to connect...

We are given a set of sensors at given locations, a set of potential locations for placing base stations (BSs, or sinks), and another set of potential locations for placing wireless relay nodes. There is a cost for placing a BS and a cost for placing a relay. The problem we consider is to select a set of BS locations, a set of relay locations, and...

We have developed SmartConnect, a tool that addresses the growing need for the design and deployment of multihop wireless relay networks for connecting sensors to a control center. Given the locations of the sensors, the traffic that each sensor generates, the quality of service (QoS) requirements, and the potential locations at which relays can be...

The key requirements for enabling real-time remote healthcare service on a mobile platform, in the present day heterogeneous wireless access network environment, are uninterrupted and continuous access to the online patient vital medical data, monitor the physical condition of the patient through video streaming, and so on. For an application, this...

In a typical enterprise WLAN, a station has a choice of multiple access points to associate with. The default association policy is based on metrics such as Re-ceived Signal Strength(RSS), and "link quality" to choose a particular access point among many. Such an approach can lead to unequal load sharing and diminished system performance. We consid...

Hand-held devices consume significant amount of energy while downloading large files or while streaming multimedia over a WLAN. IEEE 802.11 for WLANs provides PSM mechanism to reduce the energy consumption of a wireless device by allowing the wireless interface to go into sleep mode whenever possible. It is found that as stations (STAs) share the w...

We present network monitoring architecture and the implementation of 6PANview, a network monitoring system which we developed to oversee the health of a 6LoWPAN based WSN from the Internet. At the core, 6PANview uses well known standard Internet monitoring and diagnostic tools such as ping, traceroute, SNMP. We implemented a memory efficient and po...

SeaMo, a vertical handoff (VHO) implementation based on our earlier paper [1] is tested with various mobility scenarios on a mobile IP testbed using MIPv6 and HIP protocols for mobility management. SeaMo considers various parameters like RSSI, link quality metric, end-to-end available bandwidth, battery power, network usage costs etc., in making th...

We propose distributed link reversal algorithms to circumvent communication voids in geographic routing. We also solve the attendant problem of integer overflow in these algorithms. These are achieved in two steps. First, we derive partial and full link reversal algorithms that do not require one-hop neighbor information, and convert a destination-...

Wireless sensor networks are often modeled in terms of a dense deployment of smart sensor nodes in a two-dimensional region. Give a node deployment, the \emph{critical geometric graph (CGG)} over these locations (i.e., the connected \emph{geometric graph (GG)} with the smallest radius) is a useful structure since it provides the most accurate propo...

We propose partial and full link reversal algorithms to bypass voids during geographic routing over duty-cycled wireless sensor networks. We propose a distributed approach that is oblivious to one-hop neighbor information. Upon termination of the algorithm, the resulting network is guaranteed to be destination-oriented. Further, to reduce the delay...

We present a centralized integrated approach, ADWISER, for (i) managing an Internet access link bandwidth, and (ii) for enhancing the performance of an IEEE 802.11 WLAN. Our single-box approach is an extension to our previous work, where we focused on meeting TCP performance objectives over WLANs. In this work, we present a novel cascaded packet sc...

We present a low-complexity algorithm for intrusion detection in the presence of clutter arising from wind-blown vegetation, using passive infra-red (PIR) sensors in a wireless sensor network (WSN). The algorithm is based on a combination of Haar transform (HT) and support-vector-machine (SVM) based training and was field tested in a network settin...

In our earlier work, the authors proposed WLAN Manager (or WM) a centralised controller for QoS management of infrastructure WLANs based on the IEEE 802.11 DCF standards. The WM approach is based on queueing and scheduling packets in a device that sits between all traffic flowing between the APs and the wireline LAN, requires no changes to the AP o...

We propose a Split MAC (see RFC (1)) architecture based solution to enhance the Quality of Service (QoS) experienced by the wireless nodes in an IEEE 802.11b/e based WLAN. Our proposed solution achieves the objectives of a) providing a fair sharing of the wireless channel time among stations (STAs) while maximizing channel utilization in a situatio...

We provide a comparative performance evaluation of packet queuing and link admission strategies for low-speed wide area network links (e.g. 9600 bps, 64 kbps) that interconnect relatively high-speed, connectionless local area networks (e.g. 10 Mbps). In particular, we are concerned with the problem of providing differential quality of service to in...

In this paper we describe our approach to, and experiences in, developing a PC based IEEE 802.3 LAN - X.25 WAN IP router. The basic router functionality is achieved by integrating a commercially available synchronous serial port card for the PC-AT bus, and our enhancements of public domain or licensed pre-production source code for the communicatio...

We provide a comparative performance evaluation of packet queuing and link admission strategies for low speed wide area network links (e.g., 9600 bps, 64 Kbps) that interconnect relatively high speed, connectionless local area networks (10 Mbps). We are concerned with the problem of providing differential quality of service to inter-LAN remote term...