Hardware
This page lists various modules which could be used in a Homebrew Mobile Phone. NOTE: Some of these items may be hard to source in small quantities. See Suppliers for a list of goodies you can get hold of.
Cellular Wireless Modules
There are a _lot_ of different standards for cellular networks out there. They generally fall under 4 different "Generation". Wikipedia has some useful information about this: GSM Use the selector on the right-hand-side to view information about a particular generation.
Generally, each generation has a different set of frequency bands which they use, however these bands are not universal across the world with some conuntries usings one band and a different country using another. E.g. While a GSM/GPRS phone is always a GSM/GPRS phone, there are 4 different bands which are used across the world.
- 2.5G (GSM & GPRS)
- These days 2.5-generation modules are the entry point. They have GSM for voice & SMS and GPRS for data. There are different classes of device which dictate how the GSM & GPRS functionality inter-operate. For more information, try Wikipedia's GPRS classes.
Telit GE863 - A Class 10, Quad-band GSM/GPRS Module. Also features an integrated GPS module. Availability: Main_Page#GSM_Modules
Telit GM862 - Quad-band GSM/GPRS Module. Also avaliable with a Python interpreter! Availability: Main_Page#GSM_Modules
Telit GM862-GPS - Same as GM862 but with an integrated GPS module. Availability: Main_Page#GSM_Modules
- 2.75G (EDGE)
- 2.75G adds higher speeds to GPRS using a technology called EDGE.
Siemens MC75 - Class 10, Quad-Band GSM/GPRS/EDGE module. Interfaces using USB2.0. Availability: Soon (Hopefully) :-)
- 3G (UMTS)
- 3.5G (HSDPA)
- 3.5G upgrades the UMTS bitrates using a technology called HSDPA. Because of the higher bandwidths used, these modules are usually interfaces using USB 2.0. As a result, integrating them into a homebrew phone is going to require a Linux driver to be sourced or, more likely, written. It's probably best to stick to the lower speed devices - for now.
Sierra Wireless MC8775V. Availability: No Supplier Found
Siemens HC25. Availability: No Supplier Found