Subject: Re: Real Time O.S vs 'conventional' one.
To: Marcin Jessa <>
From: Jim DeLisle <>
List: tech-embed
Date: 10/26/2005 07:23:57
'Real Time' does not refer to how fast an OS runs. It refers to 
determinism. In other words, the latency between the IRQ and the ISR 
vector is consistent under any circumstances. A 'soft' real time OS, 
like WinCE, for example, does not provide this level of certainty. One 
version of real time Linux actually runs a small real time executive 
which, in turn, runs Linux as a task. The real time elements are not 
built into the Linux kernel itself, and applications that wish to 
participate in real time scheduling do so through an interface to the 

For WLAN hardware, using an RTOS probably wouldn't be getting you 
anywhere you can't get with a well configured build of NetBSD or Linux. 
I can't imagine a scenario where routing data packets would fall in the 
same scheduling priority of shutting down a malfunctioning robotic welder.

Best Regards,
Jim DeLisle

Marcin Jessa wrote:
> Hi guys.
> I have embedded boards which I want to use as acess points for WLAN
> infrastructure.
> The choice is between NetBSD and Real Time Linux.
> What I am wondering about is if there is any advantage using real
> time O.S on wireless enviroment. 
> Would one gain anything speedwise using RTOS ?
> Cheers,
> Marcin.

Swell Software, Inc.