Tuesday, April 24, 2012

University of Florida Shutting Down Computer Science Department

I honestly thought this was a joke when I first read it. The University of Florida - that's the big one in Gainesville, where Tim Tebow played football for the Gators - has decided to shut down it's computer science department. The University has decided to eliminate all funding for teaching assistants in computer science, cut the graduate and research programs entirely, and move what is left into other departments.

This will allow the University to save about $1.4 million per year. At the same time, the University is increasing the athletic budget by $2 million to $97. million. Am I blaming athletics - no. I love football! But it does look like there is more emphasis on athletics at the University of Florida after a move like this.

Where's it coming from?  It's a response to the Florida State Legislators who have cut the University budget by 30% over the next 6 years. You can read the University response in a Forbes post.

There's more.... a couple of days ago Florida governor Rick Scott approved the creation Florida Polytechnic University, a new public university that will be located in the Tampa area. The new University will involve the phasing out of the University of Southern Florida Polytechnic campus also located in Lakeland.  

Sunday, April 22, 2012

Video: I Am Worried About My Grade

With the end of the semester coming in a few weeks it's that time of year on college campuses. This is for those of you who teach. If you've been at it long enough, you've probably heard just about all of these.

Students - you need to be a little more creative and  thanks to Jean and Diane for passing this along.

Thursday, April 19, 2012

87 Million 4G Devices Will Ship In 2012

According to a recent ABI Research report, 4G devices are moving rapidly from the assembly line to retail stores.

Here's some details:
  • Refers to a range of 4G-enabled mobile devices, from USB dongles, smartphones, tablets, 4G portable hotspots, and wireless broadband CPE modems
  •  4G devices are expected to generate 87 million in unit sales in 2012, up 294% year-on-year.
  • 61 million 4G handsets being shipped in 2012.
  • 26 million 4G non-handset products (e.g. USB dongles for legacy laptops and netbooks, by premise equipment, home modems, etc) will be shipped
  • The lion’s share of the market is now backing LTE as service provider and vendor support has fallen away from WiMAX.
  • There is a natural evolutionary demand from 3G end-users, both business and consumer, to jump onto the 4G data bandwagon. 
  • Mobile device vendors are experiencing intense competitive pressure, which is expected to bring down LTE handset prices, estimated at 10 to 20 percent over the next two years.
It's not all good though. There are still some big technical issues that need to be worked out including the recent Australian iPad 3 promotion fiasco, when iPad 3s were being promoted as being ‘LTE-ready,’ even though the modem is unable to access the Australian LTE spectrum band

In addition, some customers will not be ready this year to pay a premium for 4G handsets and 4G services. 

As a reference, in a February 2012 report Forrester predicted by 2016 one billion people will own smart phones. 

Monday, April 16, 2012

Data Transmission on T-1 Carriers Part 1

Back in December I wrote a post here titled T1 Lines - What They Are. In the post I discuss the Digital Signal (DS) Level System and how combining the equivalent of 24 DS-0 voice channels along with overhead consisting of timing and synchronization bits brings the DS-1 bit rate to 1.644 Mbps - that's a T1. In this post, let's have a look in more detail to get a better idea of how the entire system works. 

The T-1 Carrier uses time division multiplexing and was designed for voice call transmission. When used for data one would think it would be possible to achieve a data bit rate of 64 Kbps over a T-1 carrier. Looking a little closer one sees that data on T-1 carriers is transmitted in the form of only 7 bit words, all eight bits are not used. Why? 

Remember the T carrier system was initially designed for voice. The first signal synchronization used for the T-1 carrier substituted a single in band signaling bit, used for control, for each of the 24 channels in every sixth frame. This means in the sixth and twelfth frames of every T-1 carrier master frame there is a bit used for in-band signaling. This is referred to as bit-robbing. Bit robbing is usually not a problem when transmitting voice. Even though the signal is slightly distorted, the listener on the receiving end cannot perceive the distortion. However this is a major problem when transmitting data as any data received with missing bits will be distorted and received incorrectly. To eliminate the problem caused by bit robbing data on the T-1 carrier is limited to seven bits per frame in all frames. By decreasing the number of bits transmitted the data bit rate is reduced.
For this reason, 56 Kbps Clear Channel Capability is the term used to refer to the T-1 carrier single channel maximum data bit rate.

T-1 Carrier Pulse Cycles
If we look closer at a T-1 Carrier signal we see there are negative and positive pulses combined in the digital pulse train. A sample T-1 signal pulse train is shown in the figure below.

Sample T-1 Pulse Train

It has been found that alternating positive/negative pulse trains (bipolar) produces fewer transmission errors than all positive or all negative pulse trains. These pulses are used to represent binary 1’s and each pulse, when non-zero, is positive half the non-zero cycle (50%) and negative half the non-zero cycle. We can look at an example of a positive (cycle 1) and negative (cycle 4) pulse from the above figure.
Sample T-1 Positive and Negative Going Pulses

In the figure above, T represents the period, or time it takes to complete a single pulse cycle. We can calculate the percent duty cycle using the following equation:

The pulses here are not zero for one half of the pulse period and have a 50% duty cycle. Let’s go back now and look at the original pulse train diagram and look at each cycle:

You can now see that if a pulse is present within a cycle time slot, whether positive or negative, it represents a 1 bit and if no pulse is present, it represents a 0-bit.

In Part 2 of this series I'll cover something called Bipolar with Zero Substitution (B8ZS) for T-1 signal synchronization.

Tuesday, April 3, 2012

Is You Legal Right To A Landline Phone Going Away?

You may not realize it but you have a legal right to have landline phone service at almost any address in the United States. The Goals of Universal Service, as outlined in the FCC Telecommunications Act of 1996 are to:

  • Promote the availability of quality services at just, reasonable and affordable rates for all consumers
  • Increase nationwide access to advanced telecommunications services
  • Advance the availability of such services to all consumers, including those in low income, rural, insular, and high cost areas at rates that are reasonably comparable to those charged in urban areas
  • Increase access to telecommunications and advanced services in schools, libraries and rural health care facilities
  • Provide equitable and non-discriminatory contributions from all providers of telecommunications services to the fund supporting universal service programs
Universal Service goes way back to 1913 when AT&T President Thomas Vail promised "one system, one policy, universal service" in return for maintaining AT&T's (at the time) monopoly. Times have changed and today, AT&T along with Verizon are saying universal landline service is costly and unfair due to a now competitive market for voice services.

Both companies have proposed a new set of rules that would allow them to only service the customers they want to service. Some say (including David Cay Johnston in a recent piece at Reuters) this roughly translates to the higher population and wealthy areas where people can afford bundled voice, video and data packages.

Johnston's piece says:
 State capitals are seeing intense lobbying to end universal service obligations but with little public awareness due to the dwindling ranks () of statehouse () reporters. 
The Utility Rate Network, a consumer advocate group, identified 120 AT&T lobbyists in Sacramento, one per California lawmaker. Mary Pat Regan, president of AT&T Kentucky, told me she has 36 lobbyists in that state working on the company's bill to end universal landline service.
Florida, North Carolina, Texas and Wisconsin have all repealed Universal Service but there have not been any cutbacks.... yet. 

Cell phones, cable and satellite are being proposed as options at least in the rural areas but there are limitations with each. Cell phones are expensive but there are packages for low income people starting at $2 per month. Internet calling is another option but expensive because it requires a broadband connection and a service. Satellite is another option but it's expensive and sometimes there are weather related connection issues.

Johnston finishes his Reuters piece saying:
We.... should not lose sight of the benefits of guaranteed access to affordable basic telephone service. The law should not force people to buy costly services they do not need.Nor should we forget that customers paid for the landline telephone system, including many billions of dollars in rate increases over the past two decades that helped AT&T and Verizon develop their cellular systems. 
If we lose universal service, I doubt we will ever get it back. Let's get a balanced policy rather than quietly rewriting laws to benefit one industry.