Elective B - Compulsory topics that appear in the elective part

 Elective B - Compulsory topics that appear in the elective part

 

Transfer speed calculation

 

MB/s ≠ Mbps

 

• Mbps = megabits per second
• MB/s = megabytes per second

• 1 GB = 1024 MB
• 1 MB = 1024 KB
• 1 KB = 1024 B
• 1 B = 8 bits ***

 

You are usually provided with

• Data size e.g. 20 MB
• Transfer speed e.g. 10 Mbps

Calculate the transfer time

 

Steps:

1. Convert the data size to bits.
   20 MB = 20 x 1024 KB = 20 x 1024 x 1024 B = 20 x 1024 x 1024 x 8 bits
   
   
2. Convert the transfer speed to bits.
   Actually it is already in bits! Mega- here stands for 1000000. i.e. 10 Mb = 10 x 1000000 bits
   
   
3. Data size/transfer speed is the answer.
   20 x 1024 x 1024 x 8 / (10 x 1000000) = 16.78 seconds.

 

Other calculations: 

• Calculate data size from transfer time and speed. 
• Calculate the number of users the devices can support using transfer speed (calculate using individual device’s speed instead of the total speed).

 

Relevant past paper:

DSE ICT Elect B(SP-2017): 2015 2b. 2016 3bi. 2017 2a, 3c.

CE CIT Elec C(2005-2011): 2006 1g. 2007 4di. 2008 3b. 2009 3dii. 2010 3ai.

 

Methods for Internet access

• Wireless network: e.g. Satellite, mobile phone network, 2G – 5G network
• Leased line (compared with broadband): fixed bandwidth (not shared with others), secure, stable and expensive

 

Relevant past paper:

DSE ICT Elect B(SP-2017): SP 3d.

CE CIT Elec C(2005-2011): 2010 2bii.

AS CA(2000-2013): 2006 10d.

 

References:

https://www.rfwireless-world.com/Terminology/wired-network-vs-wireless-network.html

https://www.actcorp.in/blog/what-is-leased-line-and-how-it-works