While I don’t have a video for you to watch the entire presentation, I do have some pictures, and I’ll post the paper and slides I presented in case any one is interested. If you have any questions feel free to post on here or email me directly and I’ll be happy to answer any of them.

J.B. Ernst and M.K. Denko, “Cross-Layer Mixed Bias Scheduling for Wireless Mesh Networks,” in Proc. IEEE International Conference on Communications (ICC), Cape Town, South Africa, 2010.

Abstract—In this paper we propose a mixed bias approach which makes use of cross layer optimization. The cross-layer parameters are based on conditions in the network from multiple layers and are used to determine resource and time allocation for nodes in the network. Unlike existing proposals, we propose to bias against several parameters such as link quality and queue size in addition to node distance. We also propose a combined mixed bias approach which takes into account multiple parameters together. The scheme is evaluated using simulation experiments. The performance results are reported in this paper.

Download the paper (pdf)
Download the presentation slides (pdf)

The biggest lesson I’ve learned this semester is that the profs in undergrad were always right. Math is very important in CS. While it may not have been apparent at the time, (I always questioned the relevance of much of it since it was all presented very abstractly and disconnected from anything I was doing in undergrad) I now find some of my math skills to be my greatest weakness as a CS researcher. This is why this past semester I have gone out of my “comfort zone” and tried a couple of courses which I would generally shy away from. First is discrete optimization (Classifications of Optimization Problems, VRP, TSP, Bin-Packing, Cutting Stock, Simplex Method, PSO, Tabu Search, Branch & Cut etc). Second is a system performance and evaluation course (Queuing Theory, Markov models, Operational Analysis, etc). In each case, I have been pushed to the limits of what I know (and what I remember from my undergrad days). On the other hand, it has been easy to identify my weakest areas in my knowledge so that I can hopefully improve in them significantly before my quals in a couple of semesters. As an added benefit, perhaps because of the perspective I have gained as a grad student, I have started to realize the larger picture and see how many of the mathematical ideas can be applied to improve the state of the art in a particular problem area.

Lastly, I have been working at formulating my research and solidifying what it is I am working towards with this PhD. The very general description is “heterogeneous wireless networks”. Within this area, I am interested in particular type of heterogeneous wireless network. It is made up of a wireless mesh network as the backbone. Instead of traditional client nodes such as laptops, pdas etc, the clients are actually other types of wireless networks, for example: 802.11 WLAN, RFID, 3g Mobile etc. There are many problems when this type of network is considered. One is the gateway placement problem (where to place gateways between the types of networks, how many etc.). Also in each sub-network, there may be a particular set of parameters which cause the sub-network to perform very well. However when the sub-networks are joined, this set of parameters may not be optimal for the entire network as a whole. The problem then is how to optimize these sets of parameters with respect to the entire network.

In a slightly related note, I am attending two wireless network conferences in Ontario in the upcoming weeks. At the end of September I am volunteering at the adhocnets 2009 conference in Niagara Falls. I am quite excited about one of the keynote speakers (Prof. Ian Akyildiz) who has written some excellent survey papers in the area. The same week I am attending the IEEE TIC STH conference at Ryerson University in Toronto. I am presenting a paper on cross layer scheduling and resource allocation in wireless mesh networks.

Update: The paper from the TIC STH Conference is available via IEEE Xplore here.

Update: Here are some pictures from the conference:

Conference Venue, Ryerson University

Welcome to the conference!

Tea break

One of the talks

I used the tracking tool to record my locations along my trip. I was surprised to find that Telus did not charge me roaming charges for using data all over the place which was great! Anyway after my long rest, I am back and will be hopefully posting some more technical computer related topics again soon. I arrived home to find myself working on a website contract for my consulting company (http://www.ernstconsulting.ca), a book chapter with some colleagues and some other small websites for some friends. So as soon as I finish all of that expect more on my blog (oh and classes start in Sept. for my PhD! so I will likely post content related to those)

Next is the price for these things. While they seem to be too expensive (monthly) to me, I am willing to pay it since I understand the costs of setting up a network in a country as spread as Canada. However if I try to tether a Blackberry or iPhone to my computer, all of the major carriers in Canada seem to add on extra costs which make it impractical. The other reason why I do like some of the blackberry models is for international use. For instance when I was in UK this past month, I couldn’t use my LG8100 phone at all. Some of the newer Blackberries supported by Rogers and Telus that I have looked at support many technologies and seem like they make work.

Anyways, this post has mostly been a rant, so feel free to leave your experiences or some suggestions on what I might do to try to get some solution to my needs. I have tried asking the sales staff at some of the places to help me out and they have been useless so far. But thats another story.

Update: I have decided on a Blackberry Storm 9530 since it supports international roaming and has many of the features I would like in a phone. It looks like I will just settle on buying a separate mobile stick for use with my laptop. I don’t want to have to worry about all of the hassle of getting the extra software & the questionable legality that is involved with trying to get data through my phone. So far I am quite happy with the phone, it is quite a step from my LG8100.

There were people from 40 different countries there and I feel like I met someone from almost every one of them at some point. There were over 300 people at AINA this year, which apparently is down from the last couple of years (where they had 4-500) but it was still a great conference for me. I will post my slides from my presentation in this post in case anyone is interested, along with a link to the paper once it is available. I submitted another paper last night for a conference in Toronto and am working on two more papers, so hopefully I’ll be travelling soon. I am trying to aim for ICC in South Africa next year.

Here are a few pictures from the conference.

Abstract:
This paper addresses the problem of scheduling in Wireless Mesh Networks (WMNs). The paper first discusses existing scheduling algorithms and classifies them based on the technique they use and their implementation frameworks.Then detailed discussions of the proposed scheduling method are presented. Simulation experiments are conducted to compare the performance of fair scheduling with the method that does not use fair scheduling. The simulation results confirm that the proposed scheduling method has better performance with respect to the metrics used for performance evaluation.

J.B. Ernst, M.K. Denko, “Fair Scheduling with Multiple Gateways in Wireless Mesh Networks”, in Proc. of the 22nd IEEE Int. Conf. on Advanced Information Networking and Applications (AINA 2009), Bradford UK, 2009.

The paper itself is available through IEEE Xplore

Here are some pictures from the day:

Preparing for the Defense before Everyone Arrives

Some Members of Pervasive Computing and Wireless Network (PerWin) Research Group, University of Guelph

Answering Questions from the Committee at Guelph

After some relaxing, a conference in UK and some business related projects I will finally have some time (hopefully) to update the site with all the projects, articles and source I have been slowly working on the past few months in between working like crazy on my M.Sc. This fall I start my Ph.D. which will likely at least start from the work I just worked on.

As soon as I get the thesis completed though I hope to post alot more new content on the blog (as well as a potential redesign since this one seems a little cluttered and busy to me). Check back soon for alot more in-depth info on using ns3 since that is what I have been using for my thesis experiments lately. Update: I am set to defend on May 18th at Guelph. Let me know if you are interested in attending, I will provide more details via email.

In other news, the University of Guelph has officially accepted me to their Ph.D program to start in the Fall of this year (still under Dr. Denko) so I am pretty excited about having the opportunity to continue my research in Wireless Networks. I am still waiting on responses from a couple of other schools (Waterloo & Calgary) so if I end up getting accepted to either of those I will have quite a decision to make. Update: I have accepted a position at the University of Guelph and will be starting there in the fall of 2009.