90 Questions
What is the duration of a frame in LTE FDD?
10ms
What is the purpose of LTE Unlicensed (LTE-U)?
To access 'extra' bandwidth in the DL using the unlicensed band
What is the main advantage of using Carrier Aggregation in 4G?
Supports higher data rates
Which feature helps conserve battery life in 3G UMTS?
Discontinuous Reception Support
What is the purpose of Non-Orthogonal Multiple Access (NOMA) in 5G?
To enable multiple access for uplink transmission
What type of routing approach is Destination Sequenced Distance Vector (DSDV)?
Proactive
In Dynamic Source Routing (DSR), what is the purpose of Route Discovery?
To find a route from the source to the destination
What is a disadvantage of Adhoc On-demand Distance Vector (AODV) routing?
First packet has large delay
Which routing approach keeps no state at intermediate routers?
Dynamic Source Routing (DSR)
What happens when a node notices a large loss using a route in Dynamic Source Routing (DSR)?
It informs the source to use a new route with the next sequence number
What does Wi-Fi stand for?
Wireless Fidelity
What is the main characteristic of WLAN attenuation?
The strength of the signals weakens as it disperses in all directions
What is the purpose of an Access Point (AP) in infrastructure mode in IEEE 802.11 architecture?
To provide backhaul and enable connectivity for nodes
Which IEEE 802.11 standard introduced Orthogonal Frequency Division Multiplexing (OFDM)?
802.11a
What does MIMO stand for in the context of IEEE 802.11?
Multiple Input Multiple Output
What frequency band is used for downlink in Ku band for satellite transmissions?
11.7-12.7 GHz
What is the main advantage of Medium Earth Orbit (MEO) satellites?
Bigger earth footprint
What is the main focus of 5G spectrum usage scenarios?
Satisfying high data rates
What is the purpose of Non-Orthogonal Multiple Access (NOMA) in wireless networks?
Uses power domain for signal separation
What is the main challenge mentioned in the context of wireless networks?
Too many bands
What is the frequency range used for 2nd Generation Systems (2G)?
450/900 MHz
What was the major limitation of the 450/900 MHz Analog system?
Capacity crunch and lacked security features
What technology was introduced in 2.5G to enable packet switching and IP-based connectivity?
General Packet Radio Service (GPRS)
What technology did 3rd Generation Systems (3G) utilize to support higher data rates?
W-CDMA
What was the motivation behind the evolution from 2G to 3G?
Need for higher data rates
Which IEEE standard introduced channel bonding and MU-MIMO?
802.11ac
What technology does IEEE 802.11ax support for uplink, enhanced Spatial Reuse, and 1024 QAM?
OFDMA
What does the Network Allocation Vector (NAV) indicate?
Time before stations can check channel idleness
Which IEEE layer includes Distributed Coordination Function (DCF) and Point Coordination Function (PCF)?
MAC Sublayer
What does Dynamic Sensitivity Control (DSC) in IEEE 802.11ax aim to optimize?
Clear Channel Assessment Threshold (CCATH)
What is the purpose of Discontinuous Reception Support in 3G UMTS?
To conserve battery life by putting the radio to sleep
What is the main advantage of Carrier Aggregation in 4G?
Supports higher data rates by allocating more than 20MHz
What is the main focus of 5G spectrum usage scenarios?
Extreme Mobil Broadband (xMBB)
What technology did 3rd Generation Systems (3G) utilize to support higher data rates?
CDMA
What is the duration of a frame in LTE FDD?
10ms
Which IEEE 802.11 standard operates in 2.5 GHz and is backwards compatible with 802.11b?
802.11g
In IEEE 802.11, what does the term 'Ad Hoc Mode' refer to?
Infrastructure mode where nodes talk to each other directly
What is the main challenge mentioned in the context of WLAN characteristics?
Error correction in wireless networks
Which IEEE 802.11 standard introduced Orthogonal Frequency Division Multiplexing (OFDM)?
802.11a
What is the purpose of an Access Point (AP) in infrastructure mode in IEEE 802.11 architecture?
To enable connectivity in home/office networks
What is the main difference between Dynamic Source Routing (DSR) and Adhoc On-demand Distance Vector (AODV) routing?
DSR initiates route discovery when needed, while AODV only discovers routes when needed.
What is the purpose of Route Discovery in Dynamic Source Routing (DSR)?
To find the route to the destination by broadcasting a route request (RREQ) to all neighbors.
What is the main advantage of Dynamic Source Routing (DSR) approach?
Intermediate routers keep no state.
In Adhoc On-demand Distance Vector (AODV) routing, what happens when a node notices a large loss using the route?
It informs the source to use a new route with the next sequence number.
What is the main challenge mentioned in the context of routing in Multihop Networks?
Adaptation of routes due to topology changes from mobility and link changes.
What technology was introduced in IEEE 802.11ac to support up to 4 users simultaneously?
Channel bonding and MU-MIMO
What is the purpose of Network Allocation Vector (NAV) in wireless networks?
Showing the time before stations can check channel idleness
Which IEEE layer includes Distributed Coordination Function (DCF) and Point Coordination Function (PCF)?
Data link layer
What does Dynamic Sensitivity Control (DSC) in IEEE 802.11ax aim to optimize?
Clear Channel Assessment Threshold (CCATH)
What is the purpose of Chapter 7 in the context of Wireless Wide Area Networks (WWANs)?
Covering spectrum re-use, cell types, and multiple access principles
What technology was introduced in 2.5G to enable packet switching and IP-based connectivity?
General Packet Radio Service (GPRS)
What was the main motivation behind the evolution from 2G to 3G?
Need for higher data rates
What was a major limitation of the 450/900 MHz Analog system?
Capacity crunch and lack of security features
What was the primary technology utilized in 3rd Generation Systems (3G) to support higher data rates?
Wideband Code Division Multiple Access (W-CDMA)
What were the crucial components in the 2G System Architecture?
Equipment Identity (IMEI) and Subscriber Identity (SIM)
What frequency range is used for downlink in Ku band for satellite transmissions?
11.7-12.7 GHz
What is the main purpose of Non-Orthogonal Multiple Access (NOMA) in wireless networks?
Isolates signals using same resources based on power level
What is the main characteristic of Low Earth Orbit (LEO) satellites?
Low latency and low-powered terrestrial devices
What frequency range does the C band operate in for satellite transmissions?
3.6-7 GHz
What is the main focus of 5G spectrum usage scenarios?
Satisfying high data rates
What frequency range is used for uplink in Ku band for satellite transmissions?
17.3-31 GHz
What is the round trip time for a signal to bounce from earth to Low Earth Orbit (LEO) satellite and back to earth?
20 to 40 milliseconds
What is the main purpose of Mobile IP in wireless networks?
Maintain existing connections without breaking
What is the main characteristic of Medium Earth Orbit (MEO) satellites?
Circles the earth at an altitude between 1,500 to 1,000 miles
What is the main focus of Non-Orthogonal Multiple Access (NOMA) in 5G?
Improves system capacity and fairness
What is the main advantage of Dynamic Source Routing (DSR) approach?
It keeps no state at intermediate routers
In Adhoc On-demand Distance Vector (AODV) routing, what happens when a node notices a large loss using the route?
It informs the source to use a new route with the next sequence number
What is the main focus of 5G spectrum usage scenarios?
Enhanced mobile broadband, massive machine type communications, and ultra-reliable low latency communications
Which routing approach would you use in a scenario with node mobility? Why/Why not?
Dynamic Source Routing (DSR), due to its route discovery only when needed and no state at intermediate routers
What is the purpose of Network Allocation Vector (NAV) in wireless networks?
To indicate the duration of time that the medium will be busy
What is the purpose of Inter Cell Interference Coordination (ICIC) in LTE?
To prevent high power on resource blocks from causing interference to each other
What is the main focus of the 5G spectrum usage scenarios?
Extreme Mobil Broadband (xMBB) with high data rates and low latency
What is the purpose of LTE Unlicensed (LTE-U) or License Assisted Access (LAA)?
Accessing 'extra' bandwidth in the DL using the unlicensed band
What technology does LTE-M (for IoT) primarily aim to achieve?
Low complexity and long battery life for low data rate applications
What is the main advantage of Small Cells, also known as Home eNodeBs (HeNBs) or Home Base Stations (HBS)?
Helping to plug indoor coverage holes and improving capacity due to extensive frequency reuse
What is the purpose of the Network Allocation Vector (NAV) in IEEE 802.11?
It indicates the time before stations can check channel idleness
What is the purpose of Dynamic Sensitivity Control (DSC) in IEEE 802.11ax?
To optimize Clear Channel Assessment Threshold (CCATH)
What technology was introduced in IEEE 802.11ac and 802.11ax to enhance data transmission?
MU-MIMO and OFDMA
What is the main function of the MAC Sublayer in IEEE 802.11?
It includes Distributed Coordination Function (DCF) and Point Coordination Function (PCF)
What is the primary purpose of Association/Reassociation in wireless networks?
To establish or re-establish a connection when roaming
What is the frequency range of operation for IEEE 802.11a standard?
5 GHz
Which IEEE 802.11 standard introduced the concept of Multiple Input Multiple Output (MIMO)?
802.11n
What is the primary characteristic of WLAN attenuation?
The signal weakens as it disperses in all directions
What is the main difference between Basic Service Set (BSS) and Extended Service Set (ESS) in IEEE 802.11 architecture?
BSS includes an Access Point, while ESS does not
What is the primary characteristic of Multipath propagation in wireless communication?
The receiver may receive more than one signal from the same sender
Which generation of mobile communication systems aimed to use the 900 MHz band and became the most successful system with over 1 billion subscribers in 2004?
2nd Generation Systems (2G)
What were the crucial components in the 2G System Architecture?
Base Transceiver Station (BTS), Base Station Controller (BSC), Mobile Switching Center (MSC), and Gateway Mobile Switching Center (GMSC)
What technology was introduced in 2.5G, enabling packet switching, IP-based connectivity, and eased migration to newer generations?
General Packet Radio Service (GPRS)
What was the motivation behind the evolution from 2G to 3G?
Requirement for higher data rates
What technology did 3rd Generation Systems (3G) utilize to support higher data rates?
Orthogonal Frequency Division Multiplexing (OFDM)
Study Notes
Wireless Network Standards and Technologies Overview
- 802.11ac introduced channel bonding and MU-MIMO, supporting up to 4 users simultaneously with 256 QAM.
- 802.11ax supports up to 8 users simultaneously, OFDMA in uplink, enhanced Spatial Reuse, and 1024 QAM.
- Network Allocation Vector is a timer showing the time before stations can check channel idleness.
- MAC Sublayer includes Distributed Coordination Function (DCF) and Point Coordination Function (PCF).
- Super Frame is a repetition interval protocol addressing contention-free PCF and contention-based DCF traffic.
- Association/Reassociation involves passive and active scans, and reassociation when roaming.
- WLAN performance is affected by channel selection/allocation, traffic awareness, and coordination selection.
- IEEE provides multi-rate capability, with lower rates being robust but providing less throughput.
- WLAN challenges include denser deployments, increasing STAs & APs, and the need to enhance Spatial Reuse.
- Dynamic Sensitivity Control (DSC) in IEEE 802.11ax aims to optimize Clear Channel Assessment Threshold (CCATH).
- Chapter 7 covers Wireless Wide Area Networks (WWANs), spectrum re-use, cell types, and multiple access principles.
- Duplex operation includes simplex and duplex modes, with Frequency Division Duplex (FDD) and Time Division Duplex (TDD) options for UL and DL.
Evolution of Mobile Communication Technologies
- Frequency modulation in 450/900 MHz Analog system was a major achievement but led to capacity crunch and lacked security features
- 2nd Generation Systems (2G) aimed to use 900 MHz band, became the most successful system with 1+ billion subscribers in 2004, and enabled international roaming
- 2G System Architecture included BTS, BSC, MSC, and GMSC, with equipment identity (IMEI) and subscriber identity (SIM) being crucial components
- Control Channels, like forward and reverse control channels, were used for paging, call setup, and responding to paging requests
- Call initiation and reception involved access requests, network location checks, and allocation of radio channels
- Handovers occurred due to signal quality drop or load balancing, involving network-initiated procedures for channel reservation and confirmation
- Global System for Mobile Communication (GSM) transitioned from 1G Analog to a 2G Digital System, combining FDMA and TDMA for efficiency
- 2.5G introduced General Packet Radio Service (GPRS), enabling packet switching, IP-based connectivity, and eased migration to newer generations
- GPRS Architecture included SGSN for data services within the network and GGSN as the default gateway to the outside world
- 3rd Generation Systems (3G) were motivated by the need for higher data rates, leading to the evolution from 2G to 2.5G to support voice, text messaging, and packet switching
- W-CDMA Technology utilized 5MHz bandwidth and employed various techniques to support higher data rates, including increased spectrum, transmit power, and antenna utilization
- The transition from 2G to 3G marked a significant advancement in mobile communication technologies, addressing the need for higher data rates and international standards.
Evolution of Mobile Communication Technologies
- Frequency modulation in 450/900 MHz Analog system was a major achievement but led to capacity crunch and lacked security features
- 2nd Generation Systems (2G) aimed to use 900 MHz band, became the most successful system with 1+ billion subscribers in 2004, and enabled international roaming
- 2G System Architecture included BTS, BSC, MSC, and GMSC, with equipment identity (IMEI) and subscriber identity (SIM) being crucial components
- Control Channels, like forward and reverse control channels, were used for paging, call setup, and responding to paging requests
- Call initiation and reception involved access requests, network location checks, and allocation of radio channels
- Handovers occurred due to signal quality drop or load balancing, involving network-initiated procedures for channel reservation and confirmation
- Global System for Mobile Communication (GSM) transitioned from 1G Analog to a 2G Digital System, combining FDMA and TDMA for efficiency
- 2.5G introduced General Packet Radio Service (GPRS), enabling packet switching, IP-based connectivity, and eased migration to newer generations
- GPRS Architecture included SGSN for data services within the network and GGSN as the default gateway to the outside world
- 3rd Generation Systems (3G) were motivated by the need for higher data rates, leading to the evolution from 2G to 2.5G to support voice, text messaging, and packet switching
- W-CDMA Technology utilized 5MHz bandwidth and employed various techniques to support higher data rates, including increased spectrum, transmit power, and antenna utilization
- The transition from 2G to 3G marked a significant advancement in mobile communication technologies, addressing the need for higher data rates and international standards.
Test your knowledge of wireless network standards and technologies with this quiz. Explore topics such as 80
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
