Q1.1 What are base stations in wireless networking? What IEEE standards are used for wireless networking?
A stationary station in a cellular wireless network, utilized for corresponding with cell telephones. A base station is the thing that connections cell telephones to a wireless bearer’s network. Then again alluded to as the cell tower or cell site, a base station is a high altered tower that is utilized to send and get voice and data transmissions from cellular telephones. These towers are frequently situated all through a city in high areas and at the highest point of structures. The photo is a case of a customary cell tower used to send and get data.
- IEEE 802.11
- IEEE 802.11a (Wi-Fi)
- IEEE 802.11g (Wi-Fi)
- IEEE 802.11b (Wi-Fi)
- IEEE 802.16 (WiMAX)
- IEEE 802.16a (WiMAX)
- HiperLAN/1 (Europe)
- HiperLAN/2 (Europe)
Q1.2 What are the differences and similarities between an IEEE 802.11 frame and an Ethernet frame?
The greater part of the IEEE 802 frame designs offer comparable attributes, including the 802.11 frame. Since the frames are comparable, it makes it simpler to interpret the frames as they move from the 802.11 wireless network to the 802.3 wired network.
One of the contrasts between 802.3 Ethernet and 802.11 wireless frames is the frame size. 802.3 frames have a greatest size of 1,518 bytes with a most extreme data payload of 1,500 bytes. On the off chance that the 802.3 frames are 802.1Q labeled for VLANs and client need, the most extreme size of the 802.3 frame is 1,522 bytes with a data payload of 1,504 bytes.
802.11 frames are equipped for transporting frames with a MSDU payload of 2,304 bytes of upper-layer data. This implies as the data moves between the wireless and the wired network, the AP might get a data frame that is too expansive for the wired network. This is seldom an issue on account of the TCP/IP protocol suite. TCP/IP, the most widely recognized correspondences protocol utilized on networks, ordinarily has an IP greatest transmission unit (MTU) size of 1,500 bytes. IP packets are generally 1,500 bytes based on the MTUs. At the point when the IP packets are gone down to 802.11, despite the fact that the most extreme size of the MSDU is 2,304 bytes, the size will be restricted to the 1,500 bytes of the IP packets.
Another distinction somewhere around 802.3 and 802.11 frames is the MAC addressing fields. 802.3 frames have just a source address (SA) and destination address (DA) in the layer 2 header. 802.11 frames have four location fields in the MAC header. 802.11 frames ordinarily utilize just three of the MAC address fields.
An 802.11 frame sent inside of a wireless circulation framework (WOS) requires each of the four MAC addresses. The substance of these four fields can incorporate the accompanying MAC addresses: Transmitter address (TA), source address (SA), destination address (OA), basic service set identifier (BSSID), Receiver address (RA). Certain frames may not contain a percentage of the location fields.Despite the fact that the quantity of location fields is distinctive, both 802.3 and 802.11 recognize a source address and a destination address, and utilize the same MAC address position. The initial three octets are known as the Organizationally Unique Identifier (OW), and the last three octets are known as the augmentation identifier.
Q1.3 To network a Windows desktop and a computer running RedHat Linux, what will you need and what steps will you take?
You can set up a home network complete with a mutual document server and print server by introducing the Common UNIX Print Services (CUPS) and Samba on a Linux desktop. Since Linux can keep running on negligible equipment and a record and print server does not require a great deal of memory or CPU assets, you can utilize an old desktop that you would typically send to the waste. Be that as it may, you will require a vast hard drive to hold everybody’s documents.
- Install Samba and CUPS on the Linux computer. Use your graphical package manager or command line tools.
- Configure CUPS to use your printer. Use the web-based graphical interface by typing “http://localhost:631″ in your browser.
- Stop the Samba services:
sudo /etc/init.d/samba stop
- Move the default configuration file to a backup:
sudo mv /etc/samba/smb.conf /etc/samba/smb.conf.bkup
- Create a new smb.conf file. Issue the following command:
sudo gedit /etc/samba/smb.conf
At that point, either make another configuration file by taking after the Samba documentation or duplicate and glue the accompanying illustration into the manager. Ensure you change the parameters to mirror your network.
- Test the smb.conf file with the following command:
- Add additional users to the Samba server:
useradd -c “New User” -m -g users -p Passwd1 newuser
- Let Samba know about the users:
sudo smbpasswd -a newuser
- Map the Windows network drives. On the Windows machine, click on “Begin” and right-click “My Computer.” Select “Guide Network Drive,” pick a drive letter and type \netbios nameuser. This will map drive to the client’s home directory on the Linux machine.
- Add the printer to the Windows machine. Utilize the Windows “Add Printer” utility.
Q1.4 What does ISO stand for? What are the five areas of network management defined by the ISO?
ISO stands for International Organization for Standardization. The ISO network management model’s five functional areas are listed below:
- Performance Management: Monitor and measure different parts of execution so that general execution can be kept up at an adequate level.
- Fault Management: Detect, separate, alert and correct errors experienced in the network.
- Accounting Management: Usage data of network resources.
- Configuration Management: Configuration parts of network gadgets, for example, design document administration, stock administration, and software administration.
- Security Management: Provide access to network gadgets and corporate assets to approved people.
Q1.5 What are the seven message types in SNMP?
Q2.1) Consider the single-sender CDMA example in Kurose & Ross (see Figure 6.5: ‘A simple CDMA example’). What would be the sender’s output (for the 2 data bits shown), if the sender’s CDMA code were (1, -1, 1, 1, -1, -1, 1, -1)?
Output corresponding to bit d1 = [-1, 1,-1, 1,-1, 1,-1, 1]
Output corresponding to bit d0 = [1,-1, 1,-1, 1,-1, 1,-1]
Q2.2 Suppose an 802.11 b station is configured to always reserve the channel with the RTS/CTS sequence. Suppose this station suddenly wants to transmit 1,000 bytes of data, and all other stations are idle at this time. As a function of SIFS and DIFS, and ignoring propagation delay and assuming no bit errors, calculate the time required to transmit the frame and receive the acknowledgment
A frame without data is 32 bytes long. Assuming a transmission rate of 11 Mbps, the time to transmit a control frame such as an RTS frame, a CTS frame, or an ACK frame is (256 bits)/(11 Mbps) = 23 usec.
The time required to transmit the data frame is (8256 bits)/ (11 Mbps) = 751
DIFS + RTS + SIFS + CTS + SIFS + FRAME + SIFS + ACK
= DIFS + 3SIFS + (3*23 + 751) usec = DIFS + 3SIFS + 820 usec
Q2.3. LAN Design for the campus layout: