Nowadays, most smartphones (or other smart mobiles) have some kind of wireless communication for short range and medium range. For short range, the most widespread technology in use is, probably, WiFi:
- standard: IEEE 802.11
- indoor range: 15m
- outdoor range: 40m
- frequency: 2.4GHz
- power consumption: 100mW
- throughput: 5Mbps
For medium range, the most widespread technology in use is, probably, GSM:
- standard: ETSI GSM
- urban range: 500m
- frequency: 1500MHz
- power consumption: 1W
- throughput: 300kbps
The differences between such technologies are mainly due to the communication protocols and the operating frequencies. Each one optimized for its own specifications.
1st Issue
Sometimes, when a technology has several updates and add-ons (as is in this case), it is not that easy to develop a simple comparison table. Therefore, does the simplified comparison above make sense or is it too unrealistic?
2nd Issue
It is well know that software developers can use WiFi features to transfer packets directly between mobiles. However, if you want to increase the range, is there any hardware constraint that would undermine using the GSM radio module (or other widespread mobile wireless technology for medium range) to transfer packets directly between smart mobiles?