1) Your device:
-You can't expect it to have 20Mbps when your modem's capability is just running max up to 7.2Mbps.
-You might be having a faulty modem, try switching your SIM card with other modems

2) Your signal coverage:
-If you are not within DC-HSPA+ coverage, then don't expect to have 20Mbps of speed. Be contented with just probably 5Mbps speed, that's probably what your tower is capable of. I know someone who was already running in joy though he only gets 2Mbps on his Maxis. Yes, he is in Mukah, Sarawak.

3) Congested with other users:
-If you are unlucky and you live in an area where there are a lot of similar users like you, be prepared with network congestion. Everyone is fighting with you. Though you might be living in a non-urbanized area, that doesn't mean your area will have good speed. All telco providers will do survey first before doing bandwidth allocation, if you area has low density of users, they will not allocate more speed to that tower. So can't do much thing about this.

4) Timing:
-Avoid performing download activities during golden hours (7-11 p.m.), this is the period where those working folks are back to home and start jamming the line. Be considerate with others. You could queue your downloads to start only after midnight when they go to bed.

5) QoS:
-Check your QoS first, it could be your area is only capped to 2480/2480.
(Credit to fruitie for her input)

It happens when the location is LTE supported but your broadband account is not authorized to register into LTE or the LTE is simply broken.
In this case, what you need to do is disable the LTE and force the modem to 3G (WCDMA).

Below is the screenshot for Huawei latest dashboard on Huawei E398

You can purchase a 3G router to share your connection.
I recommend TP-LINK MR3420 V2, it is good and having the best 3G compatibility
For more information please refer to post #5

DC-HSPA+ =/= 42000QoS

DC-HSPA+ is the technologies used the carrier on it's base station aka tower. 2 carriers of 5 MHz are used in DC-HSPA+. Therefore, it doubles the performance on HSPA

QoS is the amount of bandwidth to you by your allocated provider. Eg : You are on a speed capped package so the CELL only allocate up to 1536 bandwidth for you

I recommend using a software to save the hassle. For router, please configure it under DHCP settings.

Details and download : DNS Jumper



Steps :
1) Download and run DNS Jumper
2) Select your network adapter, in my case, I am using Huawei E398 so I choose Huawei Mobile Connect
3) Choose your favorite DNS. (Note : You can identify the fastest DNS button by clicking "Fastest DNS")
4) Click "Apply DNS" and wait for a few seconds
5) Make sure you click "Flush DNS" to allow Windows to clear the DNS cache

1) Green bar is longer = Good signal
2) RSSI number is higher = Good signal (-97 is lower than -67)
3) SNR number is higher = Good strong signal (-97 is lower than -67)

1) Find the COM port of "HUAWEI Mobile Connect - PC UI Interface" in Device Manager
2) Use CMD, cd to the folder of MDMA, launch MDMA with the command

Sufficient USB power is crucial for stability.
Laptop tends to supply less power and cause the modem to D/C easily
1) Use a Y connector.
2) Use a router. A router will supply the sufficient juice.

Antenna will greatly increase your 3G stability and performance by a large fraction and it would greatly minimize the effects of weather on your connection.
Below are 2 major type of antenna

Yagi - Designed for a ultra long range receiving, stability is not the original aim of yagi. Users on extreme countryside which totally couldn't get any signal even 2G is suggested to go for Yagi

Panel - Designed for stability and performance boosting, it boost the stability if you already on a high speed and minimize D/C. Easy installation/
Suggested for everyone as long as they got the signal.

Use something as a reflector to reflect the signal of the modem towards the tower.

The is a low cost and easy setup.

WARN : It may affect heat dissipation for the modem

http://www.tp-link.com/en/products/details/?model=TL-MR3420
-More flexible than Aztech HW550-3G as it is compatible with most USB modems.
-But you might face with data packet loss via its WiFi channels, so just play around switching between Channel 1/6/11 and set the WiFi to only B/G type.
Discussion thread: https://forum.lowyat.net/index.php?showtopic=2068482

http://www.aztech.com/prod_3g_hw550.html
- Limited compatibility with latest router and may cause problem with certain modem with newer firmware. You may need to update your router firmware
- Overall this is still a good router.
Discussion thread: https://forum.lowyat.net/index.php?showtopic=1966992

- Promising Asus performance with top class support especially for those high range N56U or N66U
- No WiFi drop outs issued and etc

Supported modem : http://wiki.mikrotik.com/wiki/Supported_Hardware#3G_cards
- Very flexible router thanks to their extensive routeros
- Come with enterprise routing and load balancing
- Might be a bit geeky in configuring but this is a enterprise grade router