Late last week when Sprint-Nextel announced their 3G femtocell, I was taken back. Sprint decided to change its strategy from charging for femtocells access to instead giving these devices away for free. Providing free femtocells was the viewpoint I believed was most beneficial for wireless carriers when I discussed this topic in depth in my femtocell research paper. When the retention of a subscriber cost along with the cost due to additional mobile usage is factored into the equation, in many situations the cost savings to a wireless carriers easily pays for the femtocell hardware. While Sprint-Nextel probably didn’t use my research, it is good to know that others agree with my findings. Keeping with similar viewpoints, a recent survey on the Wireless Industry website, FierceWireless.com, asked viewers which technology they believed would be used to offload data traffic in the future. In my paper I argued that Wi-Fi offloading was the ideal solution once 4G networks were launched, and that femtocells were only a temporarily solution due to their complexity and cost. Only 24% of respondents believed that femtocells were the solution, further bolstering my findings in my paper. Until 4G networks are widespread, femtocells are the solution and it will be interesting if other wireless carriers follow in Sprint’s footsteps.
In the past month my friend David Brenner and I have made a great deal of progress with the wind turbine remote Arduino power meter. The idea behind the project is to log the amount of power generated from the wind turbine and have the data automatically be uploaded online where it can graphed. There are similar products on the market, but they are designed for much larger turbine and solar arrays, and thus are expensive. We wanted to utilize the Arduino micro-controller as it versatile and inexpensive. With all the parts the costs is around $80, which is a fraction of the cost of other solutions.
The power meter works by reading the current flowing from the turbine. We are using a Hall Effect current sensor as it is very efficient and can handle up 30 Amps. Based on the amount of current, the sensor outputs a voltage which can then be read by the Arduino’s analog to digital input. An issue with the Arduino’s ADC is that it is limited to only 1024 values ranging from 0-5 volts. This means that the Arduino is not very accurate and can only sense a 4.8mV change. The issue we had was that the current sensor’s output voltage changes by a very small amount and the change couldn’t be read by the Arduino. To correct this, we fed the current sensor into an amplifier stage to increase the output voltage so the Arduino could read smaller current changes. The current sensor outputs 1.5v with no current, so to ensure that we weren’t amplifying the voltage when there was no current we needed to implement a 1.5v offset.
The Arduino microcontroller reads the data from the ADC input and then sends the data through the Internet to a server. We are utilizing the wireless repeater portion of the wind turbine to transport the data through the Internet. The server then reads the data and stores it in a mysql data base so graphs can be created. The Arduino sends a new power reading every one second, so the graphs can be extremely accurate if we wish. The remote power meter is currently in field trials to ensure the basic functionally works correctly.
To receive my master’s degree from RIT, I must either complete a project or a thesis. I have decided to go the project route as this will allow me some extra credit hours to work on an independent study implementing a MPLS backbone in the lab. After careful consideration of a variety of topics that I find interesting, I have decided to investigate the issue of limited spectrum for the wireless telecommunications industry. Specifically I will be researching and writing about the use of femtocells in expanding the coverage, capacity, and speed of wireless provider’s networks. Femtocells are miniature cell sites targeted for homes and small businesses where existing cellular coverage is lacking. These devices could drastically change how wireless providers operate their networks and this is what I will be investigating in my master’s project.
Femtocell Project Outline & Proposal
Sprint-Nextel finally looks like they have a plan to be successful. This week they announced they are going to partner with other companies including Clearwire and Google to deploy their WIMAX network. There were also rumors about Sprint trying to sell the Nextel brand which they spent billions to buy just a couple years ago. These are good signs because it shows that Sprint has a plan for its different networks. Sprint’s is currently running two, and soon to be three, separate networks. If Sprint could offload Nextel then it wouldn’t need support the Nextel network which is very costly to operate.
Sprint has been recently focusing a great deal of attention on its new WIMAX network, but this isn’t where their issues lie. Sprint needs to fix the problem associated with it current cellular network. Dan Hesse, Sprint-Nextel’s new CEO, seems to be making major strides in improving the brand’s image by improving customer service. Sprint needs something to differentiate it from its big rivals. Cool phones aren’t the answer and neither is a $100 everything plan. Sprint needs to embrace what the young generation wants: internet everywhere. If Sprint offered unlimited data access on all their plan’s they could win over a huge number of customers. The young generation wants to check Facebook on their phones but current data costs for most carriers are prohibitive. Teens have a huge influence, and if they tell their parents they want to switch to Sprint because it offers free access to the internet, many parents would be willing to do this. Sprint should require all of it’s phones to support EVDO and come with a good browser such as Opera Mini. Even if you get a “free” phone you can still surf the net, something that no other carrier would be capable of. A large change is needed if Sprint is going to win new customers in a saturated wireless market.
