Connecting the MC7455 in a server for full speed capability?


#1

Hey guys,

I love this company and the awesome choices of LTE modules. Im an electrical engineer graduate and really interested in learning more about utilizing wireless lte technology. If have a MC7455 and want to connect it to a server machine how exactly am I supposed to do that? If i plug it directly in an mPCIE port but then how do I get the sim card connected? Or also I could just get a usb adapter but all these USB adapters are usb 2.0. From research I seen that usb 2.0 top speeds can be around 30-40 megabytes. So arent I limiting the 300mbps speed of the MC7455 by using the usb 2.0? Are there any official adapters that let me utizilize the full 300mbps speed and that allows me to put the sim card in too?

Thanks


#2

This one is for USB 3.0.


#3

That’s m.2 though the mc7455 is mPCIE…

Also I’m just wondering if there’s an actual product manufactured by Sierra wireless and not some random company on the internet


#4

Maybe some dev kits, they are probably very expensive for what they deliver.
But there are also adapters from mpcie to m.2 like this: https://de.aliexpress.com/item/M-2-Schl-ssel-M-M2-Ultra-NVMe-NGFF-SSD-Zu-Mini-pcie-mPCIe-Verl-ngerung/32944465997.html

Doubtful.


#5

Lol why? Any other options you recommend I’m new.

So how does Sierra wireless expect us to use this with a sim


#6

Mainly because of this:
https://forum.sierrawireless.com/t/em7565-aggregating-b1-b3-does-not-work-as-expected/13861/26

You use an adapter or you have a board with exposed SIM contacts.
Example: https://omnia.turris.cz/en/


#7

:slight_smile:
About the USB speed.
let’s stick with Mbps.
USB 2.0 in high speed mode can do max 480Mbps.
The max tput of the MC7455 is 300Mbps so there is no problem.
You’ll need USB3.0 if you want to use EM7565 (600Mbps)


#8

Oh lol okay, im trying to invest a couple thousand in buying alot of these chips. So you think the MC7455 with a usb 2.0 adapter is my best option?


#9

Yes as long as your USB2.0 supports high speed mode.
USB 2.0 Full speed ~12Mbps
USB 2.0 High Speed ~480Mbps.

I regularly test throughput with USB 2.0 High speed. I getting the max 300Mbps in DL.


#10

When you guys released the MC7455 chip how did you plan for it to be installed? Im assuming you intended a use case scenario where electrical engineers embed the system with advanced design and build the sim card slot on the board themselves? In my case im trying to get the easy way out and just buy a USB adapter… Do you have a specific one you recommend? Are there any pending bug fixes/issues that may affect my use case with these? I just want to install them on a windows/linux server computer to use 100mbps LTE network on a Verizon sim card. Im trying to use 4 devices per computer.

Also, im under the impression that the regular power output 100mA usb 2.0 port gives is not enough to power the usb adapter and MC7455. What is an ideal amount of power? Is 1Amp good?

Sorry about all the questions Im trying to buy 30 of these it would be a bummer if I make a mistake so your help and honesty is greatly appreciated.


#11

USB 2.0 has 500mA. USB 3.0 has 900mA.


#12

What do you want to do?

How do you want to interface the PCIe modem to your board?

Customers are designing their own board with a mini PCIe interface.

When I’m testing the MC74xx, I’m usually using a Sierra MC devkit. This devkit has an option for USB or external power source.

Nowadays PCs can supply easily 1Amp on USB 2.0, this is sufficient for 3G and LTE.

In customer designs the power should be supplied externally and not through the USB.

I’d recommend to read the PTS which is available on the source.

https://source.sierrawireless.com/devices/mc-series/mc7455/

Have you considered a WP76xx modem?

Sierra’s Mangoh-Red devkit can be purchased on Digikey.

James