4G modem selection

[CRImier]

We're looking for a suitable 4G modem to design a breakout for. I've already developed breakouts for SIM5320 and

Requirements:

• We need a modem that will fit into the ZeroPhone dimensions - specifically, doesn't need a bulky connector and doesn't exceed 24x30mm dimensions. So, a MiniPCI-E modem won't fit, and a 30x30mm SMT modem won't fit either (thus, SIM5320 proved to be an unsuitable option, but SIM5300EA might just work out - I will attempt assembling it soon).
• We also need analog audio output/input options. So, either we need to pick a modem with those built-in (i.e. SIM5320 does have those but SIM5360 doesn't), or we need to add PCM-to-analog converters to the breakout board.
• Modem needs to be available for sourcing in QTY1 for less than $50
• Having 2G and 3G is preferably, GPS/Glonass is cool but not required

Possible picks:

• SIM7500A - 24x27mm, no analog audio, no 2G
• SIM7500E - 24x27mm, no analog audio, has GPS (likely pick)
• SIM7500SA - 24x27mm, no analog audio, no 2G
• SIM7500JC - 24x27mm, no analog audio, no 2G/3G

TODO:

• Find more - from other manufacturers?
• Add prices in QTY1

Feel free to post your links in the comments =)

[snehasj]

Timothy Woo (aka Botletics) has a little bit more info about the SIM modems, located here. He sells each of the variants (SIM7500JC looks to be out of stock right now) on his website for $42.

An alternative source is TechShip. They offer the SIM7500A, SIM7500E, and SIM7500SA for about $48, $48, and $50, respectively. Note the A and E variants offer just the modem, while the SA variant is mounted on a mPCIe card.

I have no experience with either of these vendors. Neither of the prices include shipping and/or taxes.

[Kenzo95]

I Suggest to see Sara-U2xx Series like U270 or 201 it is the smallest 3G Module just 16mmx26mm

[snehasj]

The global version of the SARA series is SARA-U201. Available at DigiKey for just under $50 or Hong Kong-based Components-Center.com for $18. Same disclaimers apply: I have no experience with either of these vendors. Neither of the prices include shipping and/or taxes.

May be worth looking into some of the IoT cellular modems. Most of them run at LTE Cat-0, Cat-M1 or NB-IoT, which have significantly lower uplink and downlink speeds than the "normal" LTE Cat-1 modules, but they are also much cheaper. Depending on the needs of the project, these may work. Otherwise, my research has unearthed no other <$50 4G global modules.

[CRImier]

@snehasj thank you, this is an awesome explanation to all these codes! I'm likely going to get these modems from Taobao, just looked it up and they're available for as low as 172RMB ($25). I was thinking about IoT options, but we do need audio support - many of the IoT options do not implement call support. Thank you for your research!

@Kenzo95 SARA-U201 seems like a capable 3G modem, and cheap at that! It only has digital audio, so we'll need to provide DAC/ADC. I'm not sure if it will end up cheaper than SIM5300, but it's physically smaller - which is good - , so it's something to keep in mind while I'm experimenting with 3G modules.

[hramrach]

If I understand the code names correctly SIM7XXXA is for America, E for Europe, JC for Japan, and G for global.

[1NFR4R3D]

Have there been any updates on 3G/4G support? I would like to help out with this.