Hi Harald,
yeah, the hardware is layer0, then I will also implement L1 code in PC side.
I have download osmo-bts source but I dont very understand the source
architecture. can you introduce the architecture or if there is a design document.
I need to know where should I implement my L1 code. and the interface with
higher layer.

On Mon, Sep 5, 2011 at 7:19 PM, Harald Welte <laforge@gnumonks.org> wrote:
Hi John,

On Mon, Sep 05, 2011 at 05:20:17PM +0800, John Wu wrote:

> We are just planning on this project which use usb based sdr board and
> will be open design and source.

In that case, what do you plan to use as layer1?  A simple SDR board
only implements "Layer 0", but what about layer1?

osmo-bts and openbsc implement layers >= 2.

So what is your plan for L1 ?

> sounds like sysmocom already working on this.

sysmocom is not building a USB based SDR, but a complete embedded BTS
product (picocell).  That's quite something different.

And while osmo-bts and openbsc are free software available in source
code, the sysmoBTS L0 (hardware) and L1 (FPGA+DSP image) are not.

So by all means, don't be discouraged from building more hardware that
interoperates with GSM related Free and Open Source software! 

Regards,
       Harald
--
- Harald Welte <laforge@gnumonks.org>           http://laforge.gnumonks.org/
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