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Infrastructure.
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InternetYour first connection

The access network

Wi-Fi, mobile radio, fibre, cable, and other links connect a device to the wider network through a service provider.

COMPONENT 02

Its job in the system

The access network is the local beginning of an internet trip. On home Wi-Fi, the radio link joins your device to a nearby access point; a broadband connection carries traffic onwards. On a mobile network, the radio connection joins the phone to an operator’s network. Either way, the wireless hop is only part of the path.

How it works

Different physical links encode information differently: radio waves through the air, light in optical fibre, or electrical signals in conductors. Link-layer mechanisms deliver frames across a local link, while IP provides an addressing and packet format that can operate across many such link technologies. A router joins the local network to another network.

Capacity is shared in different ways depending on the technology. Interference, distance, competing traffic, and provider constraints can affect experience. A device can be connected to Wi-Fi even if the broadband link beyond that access point is unavailable. The local connection and end-to-end reachability are separate facts.

A WORKED EXAMPLE / ILLUSTRATIVE

Connected locally, disconnected beyond

Illustrative example: a laptop and printer remain on the same home Wi-Fi network while the broadband connection beyond the router becomes unavailable. Their local connection may still work, even though a remote website cannot be reached. The Wi-Fi indicator therefore describes a different dependency from end-to-end internet access. This fictional arrangement does not predict every printer or router behaviour. It simply shows why a local radio link and a provider connection should be represented as separate roles in the path.

What it connects to

Access connects the device’s applications to routers and a provider’s network. The familiar household box may combine a Wi-Fi access point, router, firewall, and modem or optical interface. These are distinct functions even when they share one case. DNS and website traffic both need working connectivity to reach remote services.

Different places, different designs

Access can be fixed, mobile, community-operated, or satellite-based. Rural geography, infrastructure investment, affordability, and policy shape what is available. The global architecture does not imply equal speed, cost, or reliability everywhere. Our phone journey chooses Wi-Fi as one concrete example and labels mobile service as a variation.

Sources & further reading

Original explanations informed by these sources. Diagrams are conceptual; local systems differ.

  1. RFC 1122: Requirements for Internet Hosts — Communication Layers IETF / RFC Editor; R. Braden (editor) · 1989-10 · Source & rights record
  2. The Internet Way of Networking: Defining the critical properties of the Internet Internet Society · 2020-09-09 · Source & rights record
  3. How the Internet Works Internet Society · Not stated · Source & rights record
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