1.2 the network edge

What is the primary function of an access network?

It connects an end system or host, like a computer or phone, to the first-hop router in the larger internet.

Edge devices that run network applications are also known as _.

hosts

What are the three main categories of access networks?

Residential, institutional (e.g., company, school), and mobile access networks.

The technology that allows multiple signals to be sent on a single cable at different frequencies is known as _.

Frequency Division Multiplexing (FDM)

Why is a cable access network considered a shared network?

Multiple homes share the same physical cable link to the cable headend, potentially sharing frequency bands with neighbors.

What term describes a network that provides faster download speeds than upload speeds?

Asymmetric

What existing infrastructure do Digital Subscriber Line (DSL) networks typically use?

The existing telephone line (twisted-pair copper wire).

What is the key difference between DSL and cable networks regarding shared bandwidth?

DSL provides a dedicated connection to the central office, while cable networks share bandwidth among multiple users.

The performance and availability of a DSL connection strongly depends on what factor?

The distance from the home to the telephone company's central office.

In a typical home network, a is connected to the ISP's line, which in turn connects to a that manages local network traffic.

modem, router

What are the two broad classes of wireless networks?

Local area wireless networks (like Wi-Fi) and wide area wireless networks (like 3G/4G/5G cellular).

"Wi-Fi protocols belong to which family of IEEE standards?

The IEEE 802.11 family of protocols.

"How does the typical transmission distance of a Wi-Fi network compare to a cellular network?

Wi-Fi typically operates over tens of meters, while cellular networks can operate over tens of kilometers."

"A host sending a large file first breaks the data into smaller chunks called _.

packets"

"In addition to the user data, what does a network packet contain?

A packet header, which contains additional information dictated by the protocol."

"What is the formula for the time it takes to transmit an L-bit packet over a link with a transmission rate of R bits/sec?

The transmission time is $L/R$."

"Physical media like copper wire and optical fiber, which contain the signal, are known as _ media.

guided"

"Physical media like radio waves, where signals propagate freely, are known as _ media.

unguided"

"What type of guided media carries data as light pulses and is known for very high speeds and low error rates?

Fiber optics cable."

"What are two significant challenges associated with wireless transmission?

Signal interference from other sources and the risk of eavesdropping since signals are broadcast."

"Which short-range wireless technology is often used as a 'cable replacement' for devices like headsets and keyboards?

Bluetooth."

"What is the term for the time it takes for a bit to travel from a sender to a receiver, such as the 270ms delay to a geosynchronous satellite?

Propagation delay."