I’ve been “researching” ways to support cellular (GSM) and Wi-Fi in any devices I make and I always end up looking at pretty huge-looking “modules” which - for cellular - always seem to be aimed at “machine-to-machine” and - for Wi-Fi - always mention that they’ve got the TCP/IP stack on-board (surely the TCP/IP stack is “normally” handled by the “host” device/processor)… as if they’re all specifically made for hobby/non-dedicated devices
What I’m getting at is: there must be a “raw” way of doing it, which consumer devices use… so; what do “real” consumer devices use?
Hopefully my (confused) mindset makes sense to someone who’ll point me in the right direction
High-volume products like cell phones use “chipsets” for their front-end and utilize the application’s processor to control them. There are several manufacturers of these chipsets including Analog Devices, National Semiconductor, Qualcomm, Texas Instruments, Commquest, Conexant, Agere, Broadcom, etc. If you Google “GSM Chipset” you’ll get plenty of links.
However, be aware that it takes a considerable amount of effort to develop the circuitry and code using these chipsets. Most low-to-mid volume commercial products use GSM modules such as the Telit or SIMCom ones.
Well, my company uses the modules, mainly because much of the lab testing and qual testing (FCC, PTCRB, carrier) is already done. Handset makers build millions of units so the $30k-$100k of lab testing can be parcelled over a large number of units.
prenvo:
Hah, I just contacted Broadcom about buying their chipsets and apparently they only sell to their “tier one customers”
So much for everyone’s got to start somewhere.
When designing with these type of chipsets, there's a lot of hand-holding required by the manufacturer so they can't afford to sell them to just anyone. Also, they try to keep the the proprietary info on their products proprietary. They'll usually require you to sign a non-disclosure agreement before giving you any documentation. I work closely with a company that designs set-top boxes for the satellite-TV industry and the same thing applies there.
falingtrea:
Well, my company uses the modules, mainly because much of the lab testing and qual testing (FCC, PTCRB, carrier) is already done. Handset makers build millions of units so the $30k-$100k of lab testing can be parcelled over a large number of units.
Not only the testing cost, but the development cost. You’re looking at probably at a man-year or better to get a GSM-based radio design off the ground.
falingtrea:
Well, my company uses the modules, mainly because much of the lab testing and qual testing (FCC, PTCRB, carrier) is already done. Handset makers build millions of units so the $30k-$100k of lab testing can be parcelled over a large number of units.
Hmm. All the modules I’ve seen seem “oversized” and designed to be stripped-down hobby “editions”, rather than everything required in a bundled IC - shout at me if I’m wrong, but all the Wi-Fi modules I’ve seen seem to have things like interfaces with “up to 4Mb/s” as if that’s awesome, yet Wi-Fi is obviously a .ton. faster “normally”, and don’t give you much flexibility for things like your own TCP/IP stack :S
Maybe I’m just not looking in the right places (or misunderstand what I’m seeing)
Gsm Man:
When designing with these type of chipsets, there’s a lot of hand-holding required by the manufacturer so they can’t afford to sell them to just anyone.
Ah, nice to know there’s some “valid” reason - I just got a one liner response and lost a bit of hope
BTW: I just checked out your site and read the FAQs - does the answer about sending an HTTP request mean a module can typically do just one task at a time (one TCP/IP connection at a time)?
