Network Question

[CorylusMaxima]

At present I only have ADSL2 delivered via an old THOMSON TG585v7 and most ISPs say ADSL2 is all that's available here. However 2 degrees say I can get RBI 4G delivered via a Huawei B535 and I am trying to weigh up the pros and cons.
My home network is used by 2 wireless printers, 3 android phones and 5 PCs (incl 2 currently ethernet only desktops). The PCs are all Win10 with local accounts of 2 or 3 users each and I use the full range of network drive mappings and permissions to share any necessary files. Also as one layer of my backup strategy I send windows file history from all 5 PCs to a single external drive connected to the desktop which is running most of the time.
The thought of having to set up everything from scratch on a new network is a bit daunting so my question is can I cheat by giving a new network on a Huawei B535 the same SSID and password as my current network and have everything just continue to work as at present?

[king1]

generally yes setting the ssid and wifi key the same does work, have done that a few times before... but there are usually gotchas, for example newer modems will often have wifi set to WPA2 only by default (for security), so for older device compatibility wpa/wpa2 needs to be changed in the modem. and sometimes you get the odd device that refuses to connect and needs to 'forgotten' and reconnected.

The other thing I usually do is set the IP range to the same subnet if its different, that way you don't need to change any static IP's.  The thompson I assume is spark, had an IP of x.x.x.254 iirc, whereas pretty much everyone else uses x.x.x.1 for the gateway. 
So either need to change the new modem ip to that as well, or simply restart all devices to pick up the new settings (BUT static IP devices will need the gateway address changed manually)

The one thing you usually need to do to the new modem is add in any port forwardings you may have

You should also benefit from better wifi - if i'm not mistaken the thomson wifi was 802.11g, since then we have had N and now AC and just trickling in is AX.  New modem will probably be 802.11AC I would think.  Wifi is still generally crap for coping large files around though.

also a decent benefit you will get (and limitation of adsl) is the greater than 1mbps upstream speed.  Often the 4G (esp. if out of town) might only get similar downstream speeds (15-20+) But on a bad day they usually get you at least 5-10mbps upstream as well. 

Downside is usually higher latency - 50ms plus pings aren't unusual...  and I have seen some due to tower locations etc who were only getting 3/1 ish, but at that level it is often cutting in and out (they really shouldn't have changed to it)..

HTH

[CorylusMaxima]

Thanks so much for all that useful info.
As I currently only get maximum 4mbps download speed using ethernet, I'm hoping that it would be an improvement for me.
The iffy part for me is that the house has a lot of reinforced concrete both externally and in an internal dividing wall. There is a ranchslider with a reasonable view of the tower where I would hope to place a modem. In that location my 4G 2 degrees phone seems to have a good signal when on mobile data. Is that a reasonable indicator or are the 2 technologies  too different to tell?
If I did get it working, would I be able to use the old TG585v7 as a wireless access point if I disable DHCP and run an ethernet cable between lan ports on both routers or is it more complicated than that?

[king1]

you could find a speedtest app for your phone and test that DL speed on the cell network, it will be a reasonable approximation of what you can get.
Google might show you a speedtest option as well if you google speed test, just make sure you disable wifi on the phone... Checking ip address confirms which network you are connected too...

Although it seems to be a suggested thing online to disable dhcp to create an access point, I have never had much luck doing that - for me it has always been rather unreliable or just never actually worked...

These days I would suggest a mesh wifi network as the most reliable way to get a good wifi spread through the house. TP Link seem to do some good ones

[Agent_24]

Although it seems to be a suggested thing online to disable dhcp to create an access point, I have never had much luck doing that - for me it has always been rather unreliable or just never actually worked...

I've got an old Edimax BR-6574n set up like that, it works perfectly. Both on Ethernet and WiFi. I would be skeptical of a Thomson being any good though, they have pretty weird firmware, but why not try it and see?