Hi and welcome to this part of the forum. Forgive me if I cover stuff you already know. I just want to be sure we're talking the same language.
As a basic principle, yes, your plan to extend the Ethernet side of things works, but it won't fix the wireless.
You've used the word hub and splitter. I'm going to presume you're using the words interchangeably because its something that takes one signal cable in and then allows multiple connections to other devices, a bit like a multi-way extension socket for mains power. Also, because resellers try to cover all the different search terms that people use to find these things. The word "hub" though has a specific meaning in networking; and we generally talk about using hubs
or switches.
Perhaps the easiest way to visualise what's happening and to understand the difference between hubs and switches is to think of the computer data as cars travelling along roads (the cables). A network hub or switch is a junction point similar to a crossroads. A switch is a crossroads with traffic lights. The lights control the flow of the traffic so there are no collisions. A hub is like an unmarked crossroads. Traffic can still flow, but there's no control over it and no particular side has priority. When the network is quiet then there's not much traffic so the flow is okay. When things get busy though the unmarked crossroads doesn't help and there are lots of collisions. That's a hub.
You can buy
hubs and
switches. Both look very similar, but the way they work isn't the same. A small network switch will generally be a better (faster) solution for data traffic, particularly with applications such as Skype calls and gaming. We don't tend to use hubs so much this last 15-20 years.
If we're going with the switch idea, then your Wi-Fi router with Ethernet ports will connect to the switch - which I presume will be in the spare room(?), and then two (or) more Ethernet cables will go off to the devices in the spare room and your son's bedroom above. This
Netgear 5-port Gigabit switch is inexpensive and would work perfectly for your application.
One natural question is whether the switch will be fast enough. I can set your mind at rest here. Where you're spending around £25 per month for superfast broadband, they'll be quoting speeds somewhere from 30Mb to 70Mb; even a very basic internet router will have an Ethernet port speed of 100Mb - so, faster than the service you're getting. The Netgear switch goes up to 1000Mb. It's way faster.
If I attach a router to the new ethernet cable in the spare room would that then provide a new wifi signal? Would it be stronger in my son's room because this router would be closer than the current router?
If you mean another Wi-Fi router additional to the one downstairs, then that's not a great idea.
Technically, it's possible to do this, but it's complicated and messy unless you're very comfortable messing with router software. A much simpler solution to improve Wi-Fi coverage -
and probably improve the service if your Wi-Fi router was supplied by your Internet Service Provider (ISP) - is to add something called a Wireless Access Point, or WAP for short.
The sort of WAP we're talking about for you takes an Ethernet connection and generates a wireless signal so that Wi-Fi devices can connect to it and the networks beyond.
WAPs come in at various levels of functionality, and the prices reflect that. For the domestic WAPs with the wizards and some auto-set-up features you're looking at prices from £20 up to about £70. To gauge where to jump in, the best place to start is by understanding the wireless capabilities of the gear that will be connecting. Grab a coffee because there's a bit to take in here.
Wi-Fi uses two radio frequencies; these are 2.4GHz (been around since wireless data started, decent long distance reach but the network is crowded and prone to interference), and 5GHz which is less crowded, and supports faster data rates, but has a shorter reach than 2.4GHz. There are the wireless bands, so if you read about
Dual Band Wi-Fi it means a device that can work on either/both.
Sitting on those frequencies you have the standards of Wi-Fi and the theoretical speeds they support.
802.11b has been around the longest. It runs on 2.4GHz only, and gets up to a speed of 11Mbps
802.11g - 2.4GHz only- up to 54Mbps
802.11n - 2.4 or 5GHz - up to 450Mbps
802.11ac - 5GHz - up to 1.3Gbps
802.11ac also comes in different speeds depending on how many devices it can serve.
The wireless cards in most portable devices will cover a number of standards, so you might see the spec written 802.11b/g/n. Most devices that are listed as Wireless ac (802.11ac) will also support 802.11n.
Understanding this might seem like a bit of a bind,
but it is important. Buying a WAP without looking at whether it fills your needs for the devices you have could leave some devices unable to connect. For example, there are wireless music streamers that use 802.11b only (because it's plenty fast enough and has the best range), but if the WAP doesn't support that legacy standard then these devices won't connect. At the other end of the spectrum, you might have a new tablet that could run quite quickly on 802.11ac, but it is hobbled because a cheap WAP doesn't support it.
In general terms, recent small portable devices such as higher-end smartphones and tablets are more likely to make use of 802.11ac. Laptops unless quite recent will probably offer b/g/n. Older gaming consoles will be b/g/n but newer ones may support 802.11ac, but
[TIP] they should really be hardwired for the best performance.
Here's a useful background info:
1) Wireless is never as fast as the manufacturer claims.
The reason is speed reduces because of the way the data is packed/unpacked, and because of range, and interference, and how many devices are connecting at the same time, and in some cases because wireless for all devices runs at the speed of the slowest device. The quoted numbers are theoretical best speeds in perfect operating conditions. If you get a quarter of the speed, you're doing well. That's why wired is always faster. It doesn't have any of these issues.
2) If your wireless router came supplied by your internet supplier, then as a general rule it sucks.
Even the latest BT hubs don't do that well in speed compared to the wireless routers and WAPs that can be bought as after-market devices. Buy a decent WAP and chances are good that it will outperform wireless from an ISP-supplied router.
TL: DR
Recommended WAPs for non-techie DIY installation:
Netgear Wi-Fi Range Extender EX6120 - £40 - covers b/g/n/ac. Quick, and easy to use. Good range of features. Can be configured in different ways so is useful beyond this specific requirement
TP-Link AC1750 Universal Dual Band Range Extender - £50 - similar to the Netgear above
You might read about Mesh networking. If you haven't come across this before, it's a way of improving coverage by using several WAPs together to create a multi-connected web of Wi-Fi. The catch if you like is that you need several suitable devices all working together before the benefits become apparent. A mesh-enabled WAP on its own, or even a couple, offers no benefit for the extra cost of the tech.
If this or any other reply was helpful to you, then please do the decent thing and click the T-H-A-N-K-S button (not the like button, the Thanks button. The difference is important). It appears when you hover the mouse pointer near the Quote Multi-quote buttons. It costs you nothing. This is the proper way to show your thanks for the time and help someone gave you.
