Category: Towers of Power

Quest and I are planning to develop a people counting method based on GSM signals. Ideally this device will be able to demodulate GSM packets and extract ISMI numbers to form a list of unique devices which will be used to estimate a population. We see this as having a variety of useful applications from analyzing traffic flow to creating a grassroots means of counting crowds and events. In addition this device could also be used to gauge demand for GSM services in underserved locations. At this point we’ve tried to go through the tutorial available on RTL-SDR.com to demodulate GSM packets on our computers however, there seems to be some installation issues that may require help in office hours. We’ve been trying to learn all we can about the available data without having access to it.

I’m not exactly sure where the two assignments for this week begin and end but the two ideas I’d like to pursure include a project relevant to my thesis work and a contribution to a NYC mesh network.

My thesis project its related to “people counting” based on radio communications. Initially my plan was to use Wifi and Bluetooth but I’m curious if it’s feasible to use GSM as the core technology. What I’m able to do with Wifi is sniff packets and tally unique MAC addresses of the various wifi clients and devices sending probe requests. This number is ok in terms of counting people but theres a lot of problems with people having multiple Wifi devices in certain areas and people disabling wifi connections on their phones. GSM seems like a great solution to this problem since most people (in highly connected economies) carry only one GSM device and rarely disable its signal. I’m not sure if this is achievable by just listening to GSM and demodulating (my preferred approch) or if I would need to set up my own BTS and actually have devices connect to it. Ideally this set up can be small enough to “wear” and it would count/estimate the population surrounding it’s user. There are a lot of potential applications of this kind of people counting. It could be used by retailers to gauge for traffic in an area, by city planners to understand where people experience the most crowding, or by organizers to estimate the size of an event without relying on 3rd party data or labor intensive hand counting.

A separate project, that would probably utilize a lot of the same research, would be some kind of contribution to the NYC mesh network. It seems pretty easy to join their network at a low cost and they have a bunch of volunteer opportunities to help install and maintain infrastructure. I was thinking that it could be cool to set up a node and maybe build a short range GSM system on top of their internet connection. I don’t know how realistic this is but I like the idea of contributing to a network that may help subvert telecom monopolies and improve local communication during emergencies.

Setting up openVPN took a few hours of flipping back and forth between the documentation for openVPN, our Towers of power git hub and the virtual machine. Not to mention the obligatory google searches. I tried to do as much in the terminal as possible; using the nano editor to create the conf files and navigating the file paths. Ultimately I think I have a decent understanding of what I  did. I spent a lot of time figuring out how to generate my own CA and client keys which in retrospect may not have been necessary. One difference I had from the instructions was that I ended up having to use the sudo command a lot. I’m not sure if this means I was working in some sort of protected directory or if that was something we were intended to figure out. Either way I’m glad I seemingly got this up and running in the end. I understand how this is relevant for secure connections to to devices like a BSC but I’m still a little fuzzy on why this would be necessary exactly (I know it has to do with public vs private IPs but that concept hasn’t totally clicked yet.)

-Built to last reading-

These chapters of built to last really drove home the benefit of having guiding principles or core ideologies behind a company (or any institution). However my concern with this idea is that, as far as I understand it, it is in some conflict with the way the American corporate finance and legal system work. While a founder or CEO may appreciate the need and usefulness of core principles and favoring other ideal over profit most of our large companies are publicly traded and are majority owned by a series of atomized investors who rely on these profits exclusively. Ford may be a stable long term business but how much can that matter to a person who’s close to retirement and who holds an investment in the company through a byzantine structure of special retirement amounts, mutual funds and stock brokers. It seems like our system of investment is arranged to create un-visionary companies focused on short term profits. With this in mind It makes sense to me why many of the behemoths of Silicon Valley have adopted corporate structures that insulate founders & CEOs from their investors. This seems like a smart move to preserve the power of core principles (or at least core decision makers). But I wonder if this has its own, unaccounted costs. These chapters really made me think about what a financial system that incentivizes goal oriented organizations rather than profit hungry companies would look like.

(I have some screenshots of the terminal but I’m gonna hold of on posting them until I’m sure they don’t contain sensitive information about my computer) :/

The built to last reading seemed to really drive home a concept I’ve heard repeated multiple times, which is that a good idea is secondary to the organization and persistence that goes into making it a reality. As the author listed off numerous examples relating to the theme of – Don’t just tell time, build a clock – I kept wondering how modern tech companies, and their “leaders”, would be judged with this frame work. Apple for instance, seems as though it could fit into either category (visionary success vs. more conventional success). Similarly I wondered how modern data might confound some of the categorization that the author made. Some companies like Walmart have since seen their preeminence degrade while others like Hewlett Packard have since become nearly iconic failures of management and innovation. Citibank too was almost completely wiped out in 2008 while its “control group” alternative Chase seems to have claimed the mantle of most admired. I think the point of the first two chapters was well taken but I am often suspicious of business writing like this. My suspicion comes partly from the fact that I’m not sure if there is useful advice on how to start a generic company. I don’t deny the value in having some business education but as the author points out many of the most prominent business people in the world had no background in business planning or business school. There are so many factors that determine a companies success that it seems like a very difficult thing to model (especially when your units of data are bookshelves and . Furthermore, there is the issue of cherry picking winners and data availability. How many visionary companies for instance didn’t make the author’s list because its founder chose outcomes besides scaling up and remaining independent. Or because time, place and circumstance closed the doors available to budding entrepreneurs…. Either way I did enjoy reading these accounts of how these big name companies stated and thrived, I just wonder about the blind spot in studies like this.

IMEI:

I was able to get my phones IMEI number fairly easily. At first I found it in the settings menu on my iPhone but later realized its written on the back of my phone. The IMSI was tricker – I didn’t get it exactly – I ended up calling AT&T customer service who told me that they had, never heard of an IMSI, then found it in my account and had to ask their boss whether it can be given out. They eventually told me that they can’t give it out to me on the phone but that it could be found in/written on my SIM card. I get the sense that I could figure it out based on other ID numbers on my phone but couldn’t figure exactly where it would come from.