Question

List ALL the different type of network connections involved in the operations for each of the scenarios below. Provide an illustration for each of the scenarios.

Scenarios

1. You have just bought a new mobile phone from an online shop. You have decided to take a few snapshots of your best friend and send them to the email account of a mutual friend across the country.
2. You are driving around in an unfamiliar city and have just gotten lost. By using your mobile phone’s GPS system, you submit a request for driving directions from a nearby intersection to your destination.

Answer 1

ANSWERS..

Let's understand the first question first..

Q.(a). If i have taken a snapshot of my friend and i have to send it through through email. Then let's understand how this Email works and what types of networking requirements for sending a snapshot across the country.

## Here are the some steps how Email works step by step process given below....

EMAIL CLIENT -

An email client is a software application that is used to send, receive, store and view e-mail.

Email-server -

An email server holds and distributes e-mail messages for email clients. The email client connects to the email server and retrieves messages. An email server may also be known as a mail server, or a mail exchange server.

Sending and receiving -

To send Internet e-mail, requires an Internet connection and access to a mail server. The standard protocol used for sending Internet e-mail is called SMTP (Simple Mail Transfer Protocol). The SMTP protocol is used to both send and receive email messages over the Internet.

When a message is sent, the email client sends the message to the SMTP server. If the recipient of the email is local (i.e. at the same domain as the email originated from) the message is kept on the server for accessing by the POP, IMAP or other mail services for later retrieval.

If the recipient is remote (i.e. at another domain), the SMTP server communicates with a Domain Name Server (DNS) to find the corresponding IP address for the domain being sent to. Once the IP address has been resolved, the SMTP server connects with the remote SMTP server and the mail is delivered to this server for handling.

If the SMTP server sending the mail is unable to connect with the remote SMTP server, then the message goes into a queue. Messages in this queue will be retried periodically. If the message is still undelivered after a certain amount of time (30 hours by default), the message will be returned to the sender as undelivered.

ANSWER..

Q (b).. If i am lost in unfamiliar city then i use my GPS of my mobile and request for driving directions from a nearby interaction to my destination. But now we'll understand how this GPS works and what type of network is being used behind.

## Let's understand how GPS works.....

GPS is a radio navigation system. It uses radio waves between satellites and a receiver inside your phone to provide location and time information to any software that needs to use it. You don't have to send any actual data back into space for GPS to work; you only need to be able to receive data from four or more of the 28 satellites in orbit that are dedicated for geolocation use.

Each satellite has its own internal atomic clock and sends a time-coded signal on a specific frequency. Your receiver chip determines which satellites are visible and unobstructed (that's important and you'll read why in a bit) then starts gathering data from the satellites with the strongest signals. GPS data is slow and this is by design — satellites run on rechargeable batteries and sending a fast signal hundreds of thousands of miles would require more power — so it'll take up to a minute to get your geolocation.

Our phone's GPS receiver uses the data from these signals to triangulate where you are and what time it is. Notice the word triangulation and the mention above that foursatellites are required for GPS to work. The fourth signal is used to determine altitude so you can get your geolocation data on a map with only three signals.

So, This is how the EMAILS and GPS works.