Schedule of Talks: Fall 2012
Past Talks:
- Date: 11-30-2012
Speaker: Aditya Sundarrajan
Talk Title:XIA: Efficient Support for Evolvable Internetworking
Paper:
- Date: 11-16-2012
Speaker: Hanif Rahbari
Talk Title:Temporal Reachability Graphs
Paper:
- Date: 11-02-2012
Speaker: Mohammad Jamal Abdel Rahman
Talk Title: Adaptive Frequency Hopping Algorithms for Multicast Rendezvous in DSA Networks
Abstract:
Establishing communications in a dynamic spectrum access (DSA) network requires communicating nodes to “rendezvous” before transmitting their data packets. Frequency hopping (FH) provides an effective method for rendezvousing without relying on a predetermined control channel. FH rendezvous protocols have mainly targeted pairwise rendezvous, using fixed (non-adaptive) FH sequences and assuming a homogeneous spectrum environment, i.e., all nodes perceive the same spectrum opportunities. In this paper, we address these limitations by developing three multicast rendezvous algorithms: AMQFH, CMQFH, and nested-CMQFH. The three algorithms are intended for asynchronous spectrum-heterogeneous DSA networks. They provide different tradeoffs between speed and robustness to node compromise. We use the uniform k-arbiter and the Chinese remainder theorem (CRT) quorum systems to design our multicast rendezvous algorithms. We also design two “optimal” channel ordering mechanisms for channel sensing and assignment, one for AMQFH and the other for CMQFH and nested-CMQFH. Finally, we develop a proactive out-of-band sensing based dynamic FH (DFH) algorithm for online adaptation of the FH sequences used in the proposed rendezvous algorithms. Extensive simulations are used to evaluate our algorithms.
- Date: 10-26-2012
Speaker: Junseok Kim
Talk Title: 802.11ec: Collision Avoidance without Control Messages
Paper:
- Date: 10-19-2012
Speaker: Selda Uyanıkr
Talk Title: AutoMAC: Rateless Wireless Concurrent Medium Access
Paper:
- Date: 10-12-2012
Speaker: Harish Kumar Shankar
Talk Title: Cooperative QoS-aware Sensing/Probing Architecture and Cross-layer Protocol Design for Multi-rate CRNs
Abstract:
The intermittent nature of spectrum availability combined with the uncertainty in the channel quality makes the problem of supporting multimedia communications over the TV white spaces very challenging. In this paper, we design a QoS-aware cooperative sensing/probing architecture called QC-SPA and a cross-layer protocol, which encompasses all the essential components to efficiently support bandwidth-hungry multimedia applications. In addition to supporting multimedia flows, the proposed architecture also accommodates low-bandwidth traffic flows. Our design consists of five principal components. First, we estimate the channel usage patterns of incumbent users and use these patterns to schedule the spectrum sensing/probing process and to compute the most optimal channel for disseminating control and management information. Second, we propose an adaptive TDMA-based frame structure whose objective is to minimize the control message overhead and hence maximize the data-transmission period. Third, we propose a novel multi-channel multi-user concurrent sensing/probing scheme, which exploits the inherent multi-user diversity of the wireless system and maximizes the discovered opportunities over a given time period. Fourth, from the outcome of the channel sensing/probing process, we design a centralized data-channel allocation scheme that aims at maximizing the number admitted flows. Finally, we propose an adaptive double-threshold based spectrum sensing algorithm that minimizes the false-alarm probability in addition to guaranteeing a given degree of protection to incumbent users. This sensing algorithm is shown to increase spectrum discovery per unit time when compared with traditional fixed single-threshold based sensing algorithms. Performance evaluation results bolster the efficiency of the proposed schemes.
- Date: 10-05-2012
Speaker: Yan Zhang
Talk Title: Watchdogs to the rescue: Securing wireless TCP
Paper:
- Date: 09-28-2012
Speaker: Wessam Afifi
Talk Title: Improving Spectrum Efficiency using Micro-ACKs
Paper:
- Date: 09-14-2012
Speaker: Alejandro Proaño
Talk Title: Physical Layer Security in Wireless Networks
Papers:
- Date: 09-07-2012
Speaker: Diep Nguyen
Talk Title: Embrace Multi-antenna Techniques to Sensor and Cognitive Networks
Papers:
- Date: 08-31-2012
Speaker: Hanif Rahbari
Talk Title: Packet Detection and Recovery Techniques
Papers: