Lost? Your cellphone can show the way

Finding yourself headed in the wrong direction in an unfamiliar section of the city is pretty common. A less common but more life-critical scenario is when you find yourself wandering off the beaten path in the mountains or drifting out in the open sea.

Lost? You can be found, if you have a mobile phone with a signal.

This was how TV journalist Cesar Apolinario found his way back to his destination, as he recounted in the May 25 Funfare column of this paper’s Entertainment editor, Ricky Lo.

Apolinario went to Camiguin Island for a segment of Reporter’s Notebook. Camiguin is part of the Babuyan group of islands, located in one of the northernmost areas of the Philippines, off the coast of Aparri, Cagayan.

"We got lost at sea because Camiguin Island was covered with clouds. For hours, our boat was tossed by giant waves and I thought the end was near," Lo quoted Apolinario as saying.  

So how did he and his crew find their way to Camiguin Island? Through his cellphone.

"Every time I lost signal," said Cesar, "I knew we were going in the wrong direction, so I would ask the one manning the boat to go the other way. It happened so many times that it took us more than five hours to reach Camiguin Island. Had my Smart cellphone conked out, o kaya nag-low-batt, I doubt if we would find our way there – and back."

Apolinario’s presence of mind saved him. A cellphone’s signal strength has a direct correlation with its proximity to the serving cell site. Also, almost all cell sites are land-based. By associating the stronger signal to the nearest dry land, Apolinario was able to provide helpful directions to the boatman.

Fortunately also for Apolinario, he was using a Smart SIM card. With over 6,000 cell sites nationwide, Smart has presence in all cities and almost all the municipalities, among them the remote Camiguin Island.

If a similar scenario happens to you, what will you do? And how does mobile communication technology work in finding a subscriber’s location?

The GSM technology

The ability to know where a mobile device is physically located at any given time is an intrinsic feature of the GSM system. According to Mar Tamayo, Smart’s group head for planning and engineering, as long as your cellphone is turned on, the network has the capacity to know which is the nearest cell site serving you.

"Whenever you make a call, your cellphone sends a signal which gets picked up by the nearest cell site in the area. Your cellphone and the cell site ‘talk’ to each other. They exchange information, such as your mobile phone number and your international mobile equipment identity (IMEI), a unique number assigned to all GSM phones, as well as the call’s time stamp for billing purposes," Tamayo says.

"The cell site then relays this to its assigned mobile switching center (MSC) where it then ‘talks’ to other MSCs so that it can find the number you are calling. Whenever this process happens, your information is stored there, along with the cell site’s location code," he adds.

Even if you are not using your phone, a cell site in any area sends out a signal to page all the subscribed mobile phones in the area. It’s like the cell site asking your mobile "are you still there?" And this is done periodically throughout the day. This is done to manage traffic, capacity, efficiency of transactions and smooth handover to the next cell site.

Since an operator like Smart knows the coordinates for all its cell sites, the location of the mobile phone can be extracted up to a certain degree of accuracy. In urban areas, the cell sites of a major network like Smart are within one kilometer of each other and in the provinces, this can average from 1.5 to 3 kilometers aerial distance. 

"While this system is in place as part of the rational operations of any GSM system, we protect the privacy of our subscribers. Specific information can only be given to the subscriber or in the case of our location-based services, to someone he has authorized," Tamayo stresses.

A matter of knowledge and trust

For some years now, Smart has been offering the Person Finder, a text-based service developed with content provider ANTS (Asian Navigation and Tracking Systems Inc.). Among other things, the service has been designed to allow a subscriber to locate another Smart subscriber – with his approval and permission, of course.

So if you want to find your friend Juan, for example, you only have to type WIS <name of person you want to locate> <his/her cellphone number> and send this to 386. A P5 per location-based service message sent is charged.

Privacy concerns are addressed: Juan will receive a text message informing him that you are requesting authorization to know his location. Juan also has the option to approve or decline. He can also change the kinds of permission if he wants to via text. On top of this, by typing WIS LIST and sending to 386, Juan can see the list of persons he has authorized to know his location.

Smart’s Person Finder can be your ally when you find yourself disoriented. As the cell site-based location finder system is tied to a map, the service returns the nearest landmark of your location.

As long as you have a working cellphone with a signal, a good way to locate yourself when you are lost – whether in the city or in remote areas – is to either be enrolled or be familiar with the commands of the available location-based services of your network provider, like Smart’s Person Finder.

"Aside from just calling another person for help, you can also provide the general area or a landmark. This can allow for more informed road assistance or in extreme cases, narrow down the area of search and rescue operations," says Ramon Isberto, Smart’s public affairs head.

"You can also authorize a trusted member of the family or a friend to know your location via the Person Finder. This can be done whenever you are embarking on a journey or if you are going to a high security-risk area," he adds.

Location-based services have also given rise to other classes of applications such as Smart’s Establishment Finder, a sort of Yellow Page service that can provide street directions and PLDT’s F.A.S.T. Track Service, an application that enables businesses to keep track of vehicles, workers, and goods in transit. Smart Kid, Smart’s brand that caters to children, has the same location-based feature that allows a parent to track his child.

In other countries, location-based services are being used for localized traffic conditions, weather updates, and news as well as enrolled marketing updates for establishments. Applications are also being tested for use in elderly care, assistance for the disabled, tourism, security and forensics.   

With the launch of Smart 3G services, broadband location-based add-ons such as graphical maps can even be downloaded.