I have several Samsung devices that can use the band 40 on Optus
But then I found out sometimes I can't connect to the internet on Band 40.
I've record a video to display this issue.
The demo device is Samsung Galaxy Tab S2 SM-T719Y
Every Samsung device can view which mobile band it's using by dial *#0011#
First, you can see the tablet was in single band 40 and without any internet connectivity
After change the APN several times, the tablet will connect to other bands, eg. Band 28 and Band 7 for CA
Then the tablet will switch to Band 40 cause Band 40 has more bandwith (20MHz)
When the tablet use 2 Band 40, the download speed is fast but the upload speed is horrible.
After few minutes, tablet will stick on single Band 40 and lost the internet connection.
This problem happens on my Galaxy S7 SM-G930F, Galaxy A7 2017 SM-A720F
Samsung Australia told me that it's the problem of the mobile carrier
And Optus said I should ask the devices manufacturer.
So none of them can fix this problem.
Is anyone here got the similar problem?
Have you tried other locations - as in physically go to a different suburb that would be using a different tower?
Have you checked the Optus mobile coverage/fault page: https://www.optus.com.au/shop/mobile/network/coverage
Your tower you connect to may have an issue.
I use band 40 in my samsung devices without issue, and im sure that anyone with a samsung device on optus in a capital city would also connect to band 40 (looking at 100's of thousands devices if not more).
Optus have had band 40 (2300Mhz) for 4+ years now, so its not a new band for them.
As for the speed, Band 40 is TDD, e.g. split by time where as all others are FDD - split by frequency.
This means Optus can allocate more availability to downlaoding then uplaoding (as most traffic on a mobile network is downloading) hence the lower upload.
APN's of yesinternet or connect shoudl be the ones to check with - depending on the plan.
Is this on a single sim card or multiple simcards? - If single it would be best to get a sim repalcement at an Optus store.
Thanks for your reply and information.
My first Band 40 phone is Samsung Galaxy Alpha SM-G850Y
Same issue happened when I was in Melbourne in 2015, my solution is disabled the band 40.
Later I moved to Mildura, VIC where is a place doesn't have Band 40.
I moved to Brisbane in 2017 and got the same issue due to Samsung removed the band selection menu in their new phones.
I've asked Optus about the Tower near my location and they said they cannot find any issue on it.
I previously owned a Vividwireless service which run on Band 40 and also got lots of problem.
After the rps downgrade my vividwireless plan to 200G which is not stick to Band 40 and the internet works.
(But the plan only contains 200GB per mth, so I canceled the plan last year.)
I use yesinternet on my all devices and it still sometimes failed to connect to internet.