Who Should Read This Book
Telecom engineers—wired or wireless, circuit-switched, or packet-switched—shouldbe able to latch onto this introduction to the OpenBTS project. At the risk of spreadingthe material too thin, care has been taken to explain both the radio and IP sides ofOpenBTS. If you are a radio frequency (RF) expert, you will learn something aboutInternet telephony. If you are comfortable with SIP and RTP, you will pick up a thingor two about radio systems and protocols.Software engineers of baseband firmware, smartphone apps, or hosted services will learnabout how the mobile network itself can now be controlled and inspected at a very lowlevel. If you’re interested in debugging an application on a mobile device, OpenBTSprovides several raw interfaces to see exactly what’s going on over the air. There are alsonew data APIs your software can consume to build applications for search-and-rescue,emergency response, power optimization, roadway traffic analytics, etc.
Why I Wrote This Book
My background is mainly in VoIP. When I began working with OpenBTS, I was blissfullyunaware of how complex radio systems can be. Conversely, other people I was workingwith were radio experts but had never touched VoIP. Documentation for the OpenBTSproject is plentiful but very broad to support this wide audience of interested parties; itneeded simplification.We wanted a new book that would be able to give a complete newcomer to the technologyenough information to successfully set up their own network: get voice calls working,exchange some SMS messages, etc. This initial success should then build confidenceand let that person set out on their own.I’ve tried to mix a healthy amount of context into the step-by-step sections. Mobilenetworks are still quite complex on the GSM and RF side. Every hint helps. I’m hopingyou will be able to avoid the large gotchas when setting yours up!I also wanted the book to be interesting enough to read in the absence of hardware. Thisbook should give you enough information to scope the required resources before divinginto an OpenBTS-related project.