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Media Layers – Wired Networking

While the IoT ecosystem is usually considered to be composed of wireless devices, it is still possible to connect IoT solutions using a wired connection.

When wireless-enabled SoCs were about to be delivered to the market (i.e. ESP8266), extension devices were already available for popular embedded systems, like Ethernet Shield for Arduino boards.

Figure 1: Ethernet shields for Arduino boards.

Cooper-based wired networks also bring an extra feature to the IoT designers – an ability to power the device via a wired connection, i.e. PoE (Power over Ethernet) – 802.3af, 802.3at, 802.3bt [1]. Long-distance connections may be implemented using optic-based, fibre connections, but those require physical medium converters that are usually quite complex, pretty expensive and power consuming; thus, they apply only to the niche IoT solutions.

The mentioned optical connections do not cover so-called LiFi, as those are considered to be of a wireless nature[2].

A non-exhaustive list of some present and former wired networking solutions is presented in Table 1.

Table 1: A Short Review of the Most Popular Wired Networking Standards
Name Communication medium Max speed Topology Max range (single segment, passive)
Ethernet Twisted pair: 10BaseT
Coaxial: 10Base2/10Base5
Fibre: 10BaseF
10 Mbps Bus, Star, Mixed (Tree) 10Base2: 0.5–200 m (185 m)
10Base5: 500 m
10BaseT: 100 m (150 m)
10BaseF: 2 km (multimode fibre)
Fast Ethernet Twisted pair: 100BaseTx
Fibre: 100BaseFx
100 Mbps Star 100BaseTx: 100 m (Cat 5)
100BaseFx: 2 km
Gigabit Ethernet Twisted pair: 1000BaseT
Fibre: 1000BaseX (LX/CX/SX)
1000BaseT: 1 Gbps
1000BaseX: 4.268 Gbps
Star 1000BaseT: 100 m (Cat 5)
1000BaseLX: 5 km
Local Talk (Apple) Twisted pair 0.23 Mbps Bus, Star (PhoneNet) 1000 ft
Token ring Twisted pair 16 Mbps Star wired ring 22.5 m / 100 m (cable dependent)
FDDI Fibre 100 Mbps (200 Mbps on two rings, but no redundancy) Dual ring 2 km

Nowadays, the most popular wired networks are 10/100/1000 BaseT – twisted pair with Cat 5, 5e and 6 cables. They require the IoT system to implement a full TCP/IP stack to operate seamlessly with conventional Internet/Intranet/Extranet networks. Because it is usually out of the scope of standard Arduino Uno processor capabilities to implement a full TCP stack, there are typically dedicated processors on the network interfaces that assist the central processor or even handle all networking tasks themselves.

en/iot-open/networking2/wired.1699696327.txt.gz · Last modified: 2023/11/11 09:52 by pczekalski
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