Wi-fi - Internet at a coffee shop near you.

• Range- 300 ft on the best of days -
• Benefits - pretty widely available, familiar, localize
• Not-so-beneficial - often private, limited range, device can get forced out (this is why routers need resetting)

GSM - the mobile phone protocol.

• Range - pretty much line of site to tower.
• Benefits - Its EVERYWHERE (see: Verizon commercial),
• CONS: Cost much money per message
• ISSUES: There are a million standards
• WHERE TO FIND COVERAGE http://www.mobileworldlive.com/maps

Satellite

Iridium satellite

• satellite modem network that has had a monopoly for a while, lots of .gov use.
• Range-- everywhere outdoors, some indoor locations.
• CONS: $$$$ FYI, lowest cost option is $0.20 for a 50-character text.

EXAMPLES? http://www.rock7mobile.com/products-rockblock.php

Zigbee (Xbee) IEEE 802.15 standard.

Pro: Mid-range depending on router placement, only one device (router) needs access to the internet. Arduino libraries available. CONS: Not simple to set up

APRS (http://en.wikipedia.org/wiki/Automatic_Packet_Reporting_System)

• Requires amateur radio license.
• no encrypted transmissions/ all data public
• no commercial content

900Mhz radio

• like older wireless handset phones/baby monitors/garage door openers
• Crowded frequency band, but good distance, higher power.
• example: http://www.freaklabsstore.com/index.php?main_page=product_info&products_id=211

bluetooth: short range protocol supported by a range of devices, available as microcontroller serial modems.

bluetooth LE:

blue tooth low energy is a new bluetooth standard supported by fewer devices. Now integrated into some system on a chip packages from ARM.

NFC

very short range, low power system built on RFID.