Archive for November, 2007

Femtocell vs GAN

November 14, 2007


Wireless service providers in North America have started to market a new feature gimmick that allows a mobile phone user to reduce his/her air time while making calls from home.

Earlier this year TMobile started offering its Hotspot @Home feature nationwide. This service allows a subscriber to place calls from a mobile phone using cellular and Wi-Fi networks, whether a home wireless network or a hot spot operated by T-Mobile. You need a ‘WiFi capable phone‘ and a special service add-on, and calls are transferred automatically over between the cellular and WiFi networks. Cincinnati Bell also has a similar service – CB Home Run.

An alternate to using Generic Access Network (GAN) – formerly called Unlicensed Mobile Access (UMA) – to save on air time is to, er., have a personal cell tower right inside your home. This technology is made available to consumers using a device called Femtocell – formerly called Access Point Base Station (APBS).

This device is a scalable, multi-channel, two-way communication device extending a typical base station by incorporating all of the major components of the telecommunications infrastructure.

You plug this femtocell into your home broadband connection, and as soon as you enter your home while talking on your cellphone, it starts using the femtocell device. Sprint is running a pilot test of AIRAVE in Denver and Indianapolis, and is planning to launch this service nationwide early next year.

It remains to be seen which technology will win over the consumers eventually. From the looks of it, it appears that the WiFi option would win out just from the ubiquitous hotspots that are sprouting up all over town. With a femtocell, on the other hand, you extend your coverage only within your home.


A resurgence in Lunar Exploration

November 12, 2007


Is there a race heating up with lunar orbiters suddenly becoming the focus of several nations around the globe?

The Chang’e 1 is an unmanned lunar orbiter from China’s CLEP that entered its one-year long lunar orbit early Monday. The $187 million mission is a key stepping stone in China’s quest to develop a lunar exploration program that includes a lunar rover and a probe to return soil samples from the moon’s surface. The spacecraft is named after the Chinese goddess of the Moon, Chang’e.

Only a month back, Japan completed the launch of its own lunar orbiter – Kaguya. KAGUYA consists of a Main Orbiter at 100km altitude and two small satellites (Relay Satellite and VRAD Satellite) in polar orbit. The scientific instruments on board the Main Orbiter will be used for the global mapping of lunar surface, magnetic field measurement, and gravity field measurement. According to JAXA, the name Kaguya was inspirted by the Tale of the Bamboo Cutter.

The name KAGUYA originates from “Kaguya-hime (Princess Kaguya)” in The Tale of the Bamboo Cutter (Taketori Monogatari). and many people overlapped the images of SELENE going to the Moon on an exploration mission and Kaguya-hime going back to the Moon.

India is also planning its own launch of a lunar orbiter in April of 2008 – named Chandrayaan. Over a two-year period, it is intended to survey the lunar surface to produce a complete map of its chemical characteristics and 3-dimensional topography. Chandrayaan literally means moon-craft in sanskrit.

And finally, USA is planning to put the Lunar Reconnaisance Orbiter around the moon in October 2008. The first mission of NASA’s Robotic Lunar Exploration Program, it is designed to map the surface of the Moon and characterize future landing sites in terms of terrain roughness, usable resources, and radiation environment with the ultimate goal of facilitating the return of humans to the Moon.

Space race or not, these missions do add to the nation’s credibility for putting satellites in orbit. Apart from scouting for resources in Moon, these missions are also prove the technical merit of the nations involved, and could be a great source for technology exports.

GOOG-411’s ‘Biddy Biddy Boop’

November 10, 2007

GigaOM has a nice article on the origins of the ‘fetch audio‘ sound for Google’s GOOG-411 service. This is a free 411 service that can used to find businesses from a phone, and even connect to the business for free. The service has been around for several months now, and I am a big fan.

As the article says, the funny ‘Biddy Biddy Boop’ sound that plays while GOOG-411 is searching for the business is actually a voice recording from  Senior Voice Expert Bill Byrne.

While it would be fun to say he locked himself in a room for weeks to come up with the perfect prompt, the truth is much more simple. “I needed something quickly,” said Byrne. “So I decided to just imitate the various sounds I had worked with over the years.” It was supposed to be a placeholder.

But the human-mimicking-a-machine, “biddy-biddy-boop” sound stuck. In fact, what you hear is the original recording (with a little engineering to lower the volume and add fades). It beat out numerous other ideas, including “Jeopardy”-like hold music, and (gratefully) an aborted attempt at replicating human conversation (as in an automated voice telling you “One sec, I had it right here” as you hear papers rustling in a simulated “search”).

In case you have never used this service before, you don’t have to call in to the service to hear the voice (although I would recommend it for the sheer fun). The fetch audio file is available as an mp3 at the Google Groups | goog411 site.

DARPA Urban Challenge – Tartan Racing Wins 2007 Race

November 7, 2007


The DARPA Urban Challenge for 2007 is a 60-mile race for completely autonomous vehicles. The autonomous vehicle must prove basic navigation skills by driving on a prescribed course, and demonstrate traffic skills by negotiating a four-way intersection with two human-driven cars and another robotic vehicle. The prize money is a cool $2 million. From the 53 teams that entered the event, 11 were qualified to compete in the finals on Nov 3rd.

The event was won by the Tartan Racing Team this past weekend. Tartan Racing is a colloboration between Carnegie Mellon University and General Motors Corporation. The team used a Chevy Tahoe to build its vehicle, named BOSS. BOSS is equipped with more than a dozen cameras, lasers and radars. The complete results are available here. Some videos of the event are available at TG Daily.

In 2005, DARPA conducted Grand Challenge, which was a race for autonomous vehicles, but with other vehicles in the mix. This event was won very closely by the Stanford team running a VW Passat, the CMU team came in second, at 11 seconds after Stanley.

Having been part of the UC Robotics team and writing the code for avoiding simulated pot holes using CCD cameras as part of my thesis, I think these two events showcase some of the greatest achievements in the field of autonomous vehicle navigation.

Quote of the week – Ayn Rand

November 2, 2007

To say “I love you” one must first be able to say the “I.”

Ayn Rand