FTTC router optional?

[#1]

It's optional only if you are prepared to update the firmware and reconfigure the existing router.
Do you actually understand what the difference is between a wireless router and a wireless access point?

[#2]

AFAIK there's no charge (deferred or otherwise) for the router with the FTTC service (other than the postage), the 'upon cancellation' charge is related to the 18month contract period and lost profit if you cancel early - the cost of the router will be built into this I think whether you have the router or not.
I'd keep the new router and keep the old one as a spare (with the FTTC firmware flashed so it's 'ready to go' if needed.

[#3]

Quote from: jelv

Do you actually understand what the difference is between a wireless router and a wireless access point?

I have stated wireless access points to include those wireless access points which support ethernet WAN. It's fairly obvious that I will require a device with ethernet WAN.
A wireless router can be a multitude of devices.

[#4]

Right - you've confirmed you don't know the difference. We've made the mistake of assuming you understood things when we posted.
The existing 'router' you have performs the following functions:
[list type=decimal]

It is a modem that connects to the exchange. This gets a single public IP address from Plusnet and makes an ethernet connection available to the rest of the box. This is a WAN port and is totally internal

It is a router. A router is a way of connecting and routing traffic across multiple networks. In this case it connects the ethernet connection from the modem part of the box to your home LAN with an IP address of 192.168.0.254 or similar - this is the IP address of the gateway you see on your PC. It has a DHCP server which will allocate IP addresses to the locally connected devices. To allow multiple LAN devices to connect via the router to the internet via the single IP address given to you by Plusnet it does Network Address Translation which is where for each connection established it converts the IP addresses. The router also has a DNS server.

It is a switch. This provides the multiple physical LAN connections on the box. It passes traffic between the router part (to and from the internet) and between all the ports as well as to/from the WAP part of the router

It also contains a Wireless Access Point which is just a dumb device to carry traffic between the other ports on the switch part (including the router).

Those are all the functions you need to connect multiple devices (including wireless) to the internet and this is what the existing 'router' you have does with the existing firmware.
When you convert to FTTC you get a BT modem. This does function 1 ONLY. You can connect a single PC to it's ethernet port when the PC is given your public Plusnet allocated IP address. Alternatively you can connect what is commonly called a cable router which does functions 2 and 3 and optionally function 4 if it is wireless.
The TG582n provided by Plusnet for FTTC is functions 2,3 and 4 in one box. To do this one of the LAN ports is converted to a WAN port which you connect to the modem.
A simple WAP does function 4 ONLY. It has one ethernet port which connects to the LAN. When the TG582n is reconfigured as a WAP in bridge mode it also has multiple LAN ports so it is doing both functions 3 and 4. It does NOT do function 2 so that needs to be done by some other device. You can plug this in to one of the LAN ports on another 'router' or switch. This is often used with a long ethernet cable to get a good wireless connection in another part of the building.
There are other options and configurations, but I've left them out to just cover what you need to understand.

[#5]

Okay thanks Jelv, much appreciated.
I think I've been calling routers, wireless access points and this is where I've been confused. For example the Apple AirPort Extreme Base Station is shown as a wireless access point yet am I right in thinking this is a router (minus modem).

[#6]

So in theory I've assumed that a WAP will always do the function you described as 2)

[#7]

Excellent explanation from jelv.
One thing which has bugged me for some years is the reference to a modem. Those of us old enough remember dial-up at 56kbps know that a modem is shorthand for Modulator/Demodulator i.e. it converted a modulated analogue signal to digital and vice versa. Now, I am sure that many will correct me if I am wrong, ADSL & FTTC are digital signals, the so-called modems therefore are not. What is to be made of this?

[#8]

But the BT telephone line is analogue even for FTTC.
So IMO modem is fine 

[#9]

Quote from: knowdice

But the BT telephone line is analogue even for FTTC.

So why is it called an Asymmetric Digital Subscriber Line ?

[#10]

Modulation is done by analogue tones on the line outside of the voice spectrum.
So the device at each end needs to demodulate those tones to produce the digits.
Yes, it's Asymmetric Digital Subscriber Line but I would contend that on the line it's analogue...

[#11]

As I understand it  ADSL/ Broadband  functions on the princciple of many virtual modems working simulatneosly over the POTS circuit.  In the 'old days' we had only one 56k modemusing audible tones,  but standard ADSL bonds together a bunch of virtual modems (up to 512 ) using diffiernt non audible tones ( see my image below. )
How many more tones does VDSL add?

[#12]

this is what mine shows

[#13]

So a lot more tones and a lot more virtual modem paths