[FoRK] Portable hotspots (or, why the iPad doesn't need 3G / future of Bluetooth questionable?)

Stephen Williams sdw at lig.net
Tue Feb 2 09:32:42 PST 2010

Jeff Bone wrote:
> Have already mentioned by reservations about 3G in the iPad.  I'm 
> certainly not going to go down that road;  entertained the thought 
> briefly, but have concluded that it's stupid.  (Like removable media 
> before it, this idea of a direct WAN connection + Wi-Fi in every 
> mobile device is daft.  That won't keep millions from buying into the 
> notion before they find that the friction of having to manage this on 
> lots of devices becomes prohibitive.)
> Here's the solution:  portable WAN-connected personal hotspots.  The 
> Verizon MiFi and similar devices have started to appear all over the 
> place --- I first saw this device category appear a couple of years 
> back with high-end aftermarket auto outfitters offering a solution 
> (other than e.g. tethering your phone.)  In general, I think the 
> extrapolation of this category --- the full-fledged, always-on, 
> WAN-connected *personal server* / gateway machine for a constellation 
> of Wi-Fi enabled devices --- is pretty compelling.  But even as a pure 
> networking device, it's useful enough that I'm seriously considering 
> adoption of this as a "tool to rely upon / organize around."
> FWIW, I also think that it's possible that such things *might* 
> undermine the market for Bluetooth devices.  There's really no good 
> need for two separate radios in any given device, IMHO.  Aside from 
> power concerns, there's no reason that Wi-Fi cannot (and should not) 
> service all the needs that Bluetooth presently serves.  The protocol 
> stack functionality can easily (and better, I would argue) be layered 
> on top of Wi-Fi / IP / ...
> Thoughts / feedback?

I've been carrying a portable hotspot with me for several years now 
using a series of USB dongle (i.e. modem) devices with a Cradlepoint 
handheld router.   You really can't beat it: just plug it in, wait 5-15 
seconds, and you're connected via WiFi on every device. 

I have also tethered my phones (all the way back to the Treo 300) via 
USB, lately, Bluetooth and Wifi.  Palm Pre and Android phones are 
capable of wireless tethering now.

I also have a battery driven Cradlepoint OEM'd as WiPipe that will drive 
my 4G WiMax USB modems.  I've measured over 3.5Mb down and 1Mb up 
(capped, the transmission is symmetrical).

So, I agree, as a practical matter this is the way to go.  I need a 
separate device so that I can be on the phone at the same time and also 
avoid draining the phone battery.  For a variety of reasons, including 
both data/voice per $ / coverage (including free roaming on Verizon) / 
4G availability, I use Sprint.  So, no voice & data on the phone at 
once, but great data almost everywhere.

Bluetooth and ZigBee will have their uses.  It is unlikely that anyone 
will bother porting all of the protocols over to WiFi.  Additionally, 
the economy of scale is already enough that the marginal cost of another 
radio is nothing.  Not to mention that WiFi, BlueTooth, and ZigBee all 
have drastically different power / data rate optimizations that are 

Maybe we'll end up with a software radio with some parallelism and an 
antenna array to handle about anything.

Having 3G built-in is a great convenience, however unless it is your 
only WWAN unit (unlikely) having another account is just a waste of (a 
lot of) money.
> jb


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