Analysis - Is GPS the next must-have mobile phone feature?

[HEXUS]

UK GPS antenna maker Sarantel is betting its future on a boom in location based services accessed through phone handsets.

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[piggeh]

I already have GPS in my handset! Sat Nav is useful - beyond that, what LBSes could be offered that could not be achieved via wifi or 3G? If it was a free service, paid for by sponsors or suchlike, it could work in certain environments (eg If you're in London it could tell you events for that night nearby), but I see little advantage if it was a commercial enterprise that end users had to pay for, otherwise they could access a much greater range of information by using mobile internet and searching google.

[jimbouk]

Just so long as there's an off setting then I'll be happy.

[Betty_Swallocks]

It already is as far as I'm concerned.

What with satnav which means I don't have to buy and carry around an additional device and Google maps which helps me find services in unfamiliar areas it's become invaluable to me.

[Funkstar]

Next must have feature?

It already is a must have feature! Yes I know Hexus readers are usually ahead of the curve on things like this, but I've had GPS on my phone since December last year.... and it's awesome!

I don't have any satnav software installed but Google Maps Mobile is good enough and extremely useful. There is also something particularly geeky about being able to load see where the satelites you are connected to actually are in relation to you (http://www.visualgps.net/VisualGPSce/)

[Salazaar]

Likewise, I'm not sure about the benefit of location based services (I guess it remains to be seen what sort of thing they might deliver), however GPS is certainly a must have feature I look for in phones these days.

[Mblaster]

I don't currently have GPS in my phone, but my next phone will definatly have it. Purely so I can use it for GPS navigation, can't think of any LBSs that I'd be interested in paying for.

[TheAnimus]

Again with the next?

Those of us who bought a smart phone in the last 18 months, and didn't stupidly buy an iPhone, have demanded it.

The n95 made it the norm with its launch, the problem being it simply took far too long to acquire a lock, once aquired it was woefully inacurate. Sitting in creamfeilds, on the top of a hill, with clear line of sight, a lock took over 30 seconds, and had an acuracy of only 20m.

But fast forward to the likes of the glofiish, and it acquires within 5 seconds (often less for a simple inacurate 2d fix) with a geocaching friendly <1m accuracy.

I guess it depends what budget we are looking at, if we mean the same way its very hard to buy a phone thats not got a colour screen or polyphonic ringtones, then yes, GPS will be that, but its not going to happen any time soon. Just look at the phones which nokia still offer without their frankly excelent mapping softawre.

[chrestomanci]

I think Sarantel are exaggerating when they say that their better antennas allow better GPS accuracy. Now that the American military have turned off selective availably, The inaccuracies in GPS mostly come from the ionosphere. The only way to get round that is to do differential GPS, which is nothing to do with your primary antenna.

A better antenna might allow a slightly stronger signal to be received, and so allow your GPS device to maintain lock while in your pocket, but I don't think existing GPS antennas are that poor, so there will not be much room for improvement. Also all GPS receivers can maintain lock from a much weaker signal than they need to get a fix in the first place, so the pocket trick is not hard. My seven year old Garm eTrex could easily maintain satellite lock inside my car glove box, where the signal attenuation is probably much greater.

The photo of the GPS antenna is of a helical coil type with a ceramic dielectric, which is not the type you would use in a cell phone, as it is quite directional, and will not work if it is not pointing at the sky. Most cell phones use ceramic patch antennas instead which are omnidirectional.

[Saracen]

GPS in a phone certainly isn't must-have for me.

For me, one of the must-have aspects of a GPS is a clear, bright and decent-sized screen. That pretty much excludes phones. But I use a sat-nav almost exclusively for driving, not walking about. On the rare occasions when I need GPS on foot then yes, it'd be useful in a phone. But I can get away with using my car Garmin handheld, or my car TomTom handheld, or my PDA TomTom handheld. Do I need it in a phone? Nope.

What I want from a phone is a small, light device that makes and receives calls, has a few memories and has a decent battery life. I don't even care if it will let me send text messages, let alone whether it has a camera, MP3 player, will let me browse the web, contains a SatNav or has a built-in washing machine and tumble-dryer.

I'm one of those boring types that just wants a phone for phone calls.

But am I typical? I rather suspect not.

[menthel]

I use the gps in my iphone every so often. I always get lost in central london and have been directed correctly by it a number of times!

[Saracen]

Originally Posted by menthel

I use the gps in my iphone every so often. I always get lost in central london and have been directed correctly by it a number of times!

That's true, and it can be useful like that. But personally, I dislike cities generally and detest central London with a vengeance. It needs something approaching a global emergency (or in one of my more mercenary moments, a very good earning opportunity) to get me into London at all.

[menthel]

Originally Posted by Saracen

That's true, and it can be useful like that. But personally, I dislike cities generally and detest central London with a vengeance. It needs something approaching a global emergency (or in one of my more mercenary moments, a very good earning opportunity) to get me into London at all.

I have to agree. I bloody hate central London but unfortunately the in-laws live in St John's Wood so we often meet them in various places for dinner etc. My wife also insists on going to the theatre etc. I can only see 1 redeeming feature- food!

[TheAnimus]

actually, toptable or GPS, on your mobile phone, i mean if you HAD to choose?

[[GSV]Trig]

I remember when I got my first mobile phone, I asked the sales guy if it had games on it, he said if you want games buy a f'ing gameboy...

Ahhh them were the days...

[SARAC]

Originally Posted by chrestomanci

I think Sarantel are exaggerating when they say that their better antennas allow better GPS accuracy. Now that the American military have turned off selective availably, The inaccuracies in GPS mostly come from the ionosphere. The only way to get round that is to do differential GPS, which is nothing to do with your primary antenna.

A better antenna might allow a slightly stronger signal to be received, and so allow your GPS device to maintain lock while in your pocket, but I don't think existing GPS antennas are that poor, so there will not be much room for improvement. Also all GPS receivers can maintain lock from a much weaker signal than they need to get a fix in the first place, so the pocket trick is not hard. My seven year old Garm eTrex could easily maintain satellite lock inside my car glove box, where the signal attenuation is probably much greater.

The photo of the GPS antenna is of a helical coil type with a ceramic dielectric, which is not the type you would use in a cell phone, as it is quite directional, and will not work if it is not pointing at the sky. Most cell phones use ceramic patch antennas instead which are omnidirectional.

I am part of the Sarantel Engineering team and would like to clarify a few key points about our claims and Chrestomanci's comments. While it is true that ionospheric interference and variation can limit the performance of single frequency/non differential GPS receivers this is only the case if you are receiving 6-8 satellites consistently and the satellites are equally spaced across the sky. The Ionosphere limit would apply if users were trying to get sub metre accuracy from GPS. Current Mobile Phones achieve 10's of metre accuracy (in some cases only 100's of metre accuracy), due largely to limitations in their antennas.

Sarantel have surveyed a number of phones and the majority of phones are using small chip or PIFA antennas. Patch antennas are large and do not enable slim phones. All these antennas have large nulls in their pattern, which leads to regions of the sky where satellites can not be tracked. As Chrestomanci points out a good antenna should be omni-directional. Although I would contend it needs to be omni-directional above the horizon only, otherwise the user is likely to be susceptible to mult-path signals.

To achieve good positional accuracy (within a few metres) you need to track satellites in all portions of the sky (think simple triangulation). Ideally you would track 3 low elevation satellites spaced 120 degrees apart on the compass and have one satellite directly above to give an accurate 3D fix. The satellite constellation is not evenly spaced, often having groupings of satellites in one part of the sky. Start adding in buildings obscuring satellites and it becomes clear how important it is for an antenna to have equal performance in all areas of the sky (above the horizon). If the antenna has nulls in it's pattern it will miss tracking satellites in a quadrant of the sky and the accuracy of triangulation will suffer greatly.

The Sarantel antenna has been designed to produce this omni-directional pattern when embedded into a phone. We have demonstrated this is possible by fitting an antenna to an existing GPS enabled phone.

We believe the usage model for GPS in mobile phones will be pocket or handbag carried, using audio commands to navigate etc. Has anyone tried walking through London with a phone in your hand? I have and I spent my whole time trying not to walk into people and lamp posts. I would much prefer to have the phone in my pocket.

Using a phone in a pocket is much tougher than the hand because the antenna is loaded by the body. Loading from the body with other antennas significantly reduces the signal level of the satellites and in some cases increasing the nulling of the antenna pattern. The ceramic loading technic we use for our antennas minimises the amount of this loading and allows navigation in the pocket.

How would you envisage carrying your phone to navigate or for LBS in cities?