What frequency range does UHF cover?
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300 MHz to 3 GHz.
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What frequency range does UHF cover?
300 MHz to 3 GHz.
What are the characteristics of wireless communication?
Convenience, reduced cost, faster deployment, mobility, unreliable channel, complicated design and management, device limitations, limited bandwidth, and expensive service.
What is Erlang B used for?
Calculating the probability of blocking for a new call in a telephone system.
In wireless communication, what is a handoff?
The process of transferring an ongoing call or data session from one channel connected to the core network to another.
What is Erlang C used for?
Calculating the probability of delay for a blocked call in a telephone system.
Who initiates the handoff in wireless communication?
The mobile device or the base station.
What are the characteristics of the early pre-cellular wireless system?
Highly-elevated, high-powered antenna, small number of channels, analog transmission, inefficient use of spectrum, very low capacity, and power-inefficient.
What does WiMAX stand for?
Worldwide Interoperability for Microwave Access.
What is a BSS without an AP called?
An ad hoc network.
Who invented the wireless telegraph and in which year?
Guglielmo Marconi invented the wireless telegraph in 1896.
What is the range of the radio layer in Bluetooth?
10 meters.
What are the key concepts of the cellular wireless system?
Low power transmitter system, increased network capacity, frequency reuse, building a robust scalable system, and architecture to deal with different user densities at different places.
What are the most valuable segments in terms of frequency?
Cellular/PCS/3G, Fixed Wireless, Satellite.
What does WiMAX provide in terms of communication standards?
Wireless broadband communication standards based on the IEEE 802.16 set of standards.
What is a BSS with an AP called?
An infrastructure network.
What was the first public mobile (car-based) telephone system introduced and in which year?
The first public mobile (car-based) telephone system (MTS) was introduced in 1946.
What are the different generations of wireless communication systems?
2G, 3G, 4G, 5G.
What are the different generations of wireless communication systems?
2G, 3G, 4G, 5G.
What has experienced rapid growth in the last decade in wireless systems?
Cellular/PCS voice services.
What are the characteristics of first-generation (1G) cellular phone standards?
Analog transmission technology, focus on voice, almost non-existent data services, incompatible standards, inefficient use of the radio spectrum, and separate frequencies.
What is the purpose of handoff strategy in cellular systems?
To find a new base station and process handoff when a user is mobile, especially when crossing a cell boundary while continuing the call.
How many channels is the 2.4-GHz ISM band divided into in Bluetooth?
79 channels of 1 MHz each.
What are the different generations of wireless communication systems?
2G, 3G, 4G, 5G.
What are some examples of wireless technologies that have seen widespread implementation?
802.11b, 802.11a, Bluetooth.
How is WiMAX similar to cellular networks?
It is similar to cellular networks in terms of traditional base station infrastructure systems.
What does TDMA stand for in the context of 2G?
Time Division Multiple Access.
What are the two WLAN-MAC sub layers?
Distributed co-ordination functions, Point co-ordination functions.
What are the specific duties of L2CAP in Bluetooth?
Multiplexing, segmentation and reassembly, quality of service (QoS), and group management.
What is the main technique used in cell sectoring?
It uses directional antennas and desired antenna placements.
How can coverage and capacity be improved in cellular systems?
Through cell splitting, sectoring, and microcells.
What does CDMA stand for in the context of 2G?
Code Division Multiple Access.
How can different frequency bands (channels) be used to transmit information?
In parallel and independently.
What are the advantages of 5G's cloud-based network architecture?
Power efficiency, easy maintenance, and upgrade of hardware.
What is TDMA in the context of 2G technology?
Time Division Multiple Access.
What data rate was required for pedestrians in the 3G communication system?
384 kb/s.
What is the frequency band used for wireless connectivity in building/office/campus areas?
License free 2.4GHz ISM band.
Which IEEE standard covers the physical and data link layers for wireless LAN (WLAN)?
IEEE 802.11.
What is the definition of 'Portable' in the context of radio terminals?
Hand-held and used at walking speed.
What are some challenges of 4G technology?
Expensive hardware and infrastructure, costly spectrum, and time-consuming deployment and upgrade.
What are the limitations of 1G networks?
Incompatible networks, limited capacity for expansion, limited support for roaming, susceptible to interference, poor security, no support for wireless data, and no support for third party applications.
What is the transmission technology used in first-generation (1G) cellular phone standards?
Analog transmission technology.
What type of telephony is associated with 1G in cellular network generations?
Analog cellular telephony.
What is the point coordination function (PCF) in WLAN-MAC sub layers?
An optional access method implemented on top of the DCF, mostly used for time-sensitive transmission.
What is UWB and how is it growing in the wireless industry?
UWB is a growing technology in the PAN (Personal Area Network) segment of wireless systems.
What frequency range does WLAN cover?
2 GHz.
How many timeslots are there in one TDMA frame in 2G?
8 timeslots.
What is the latency range offered by 5G technology?
In milliseconds, which is significant for mission critical applications.
What are the two competing standards for 3G technology?
CDMA2000 and another standard.
What is the umbrella cell concept in handoff strategies?
It involves a large cell with a powerful tower to handle high-speed vehicles and small cells for low speed.
What is the example given for the allocation of a spectrum over a base frequency for communication between stations A and B?
Assuming a spectrum of 90kHz is allocated over a base frequency b.
What are some examples of PAN (Personal Area Network)?
Body Area Network, Offline Network, Home Office.
What is the advantage of Cdma2000 3X?
It offers a more seamless, less expensive upgrade path since it allows the same spectrum, bandwidth, RF equipment, and air interface framework to be used at each base station, and 3G upgrades can be introduced over time.
What are the standard services that can use packet switching in 2.5G?
WWW browsing, email, file downloading (e.g. mp3), Multimedia Messaging Service (MMS).
What wireless technology is used for 4G?
LTE and LTE advanced.
Why was it impossible to roam between European countries with a single analog phone?
Due to incompatible standards at different frequencies.
What are the different generations of wireless communication systems?
2G, 3G, 4G, 5G.
Who can initiate handoff in cellular systems?
It can be initiated by the network (tower determines), terminal (user helps the tower), or user (user determines).
What are the three types of stations in WLAN?
No-transition station, BSS transition station, ESS transition station.
What is the technology associated with Broadband Wireless Access?
WiMAX.
How can coverage and capacity be improved in cellular systems?
Through cell splitting, sectoring, and microcells.
What is the minimum spectrum allocation for Wideband CDMA (W-CDMA)?
5MHz.
What is the characteristic of Half-duplex communication?
Same radio channel for both transmission and reception (push-to-talk).
What does cell sectoring aim to improve?
It aims to improve by increasing SIR and decreasing cluster size.
What is High-Speed Downlink Packet Access (HSDPA)?
An enhanced 3G mobile telephony communications protocol in the High-Speed Packet Access (HSPA) family.
What is Bluetooth?
A wireless LAN technology used to connect devices of different functions.
What technologies power the transmission and receiving capabilities of 4G?
MIMO and (OFDM) technologies.
When was the first commercial cellular phone system deployed in Japan?
What is the frequency range for UNII (802.11a)?
5 GHz.
What security features were introduced by TDMA?
Authentication and encryption.
What is the standard deployed in metropolitan areas of Japan in 1989 to provide higher capacity than the NTT system?
JTACS.
What are some of the services provided by 2G technology?
Improved standard telephony, basic wireless data, call barring, and more.
What does WiMAX offer in terms of Internet access?
It provides at-home or mobile Internet access across whole cities or countries.
What access method does DCF (Distributed Coordination Function) use in WLAN-MAC sub layers?
CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance).
What are some favorable technology trends in wireless systems?
Availability of a pervasive data network, innovative internet-based applications and services, personalized information retrieval, access to airline reservations systems, online trading, novel terminal devices, and emerging wide-area wireless packet data services.
What are the improvements in 2G digital systems compared to 1G?
Modest data support along with voice, cheaper faster smaller power efficient components, improved voice quality due to error coding, higher capacity, spectrally efficient modulation schemes, advanced compression and encryption techniques, and equalizer to compensate for frequency-selective fading.
How does cell splitting affect the number of base stations?
It increases the number of base stations.
What is the key feature of 3G in cellular network generations?
High-speed digital cellular telephony (including video telephony).
What is the 'make before break' handoff?
It is a type of handoff where the new connection is established before the old one is broken.
What are the characteristics of each channel?
Fixed frequency bandwidth (in kHz) and capacity (bit-rate).
How does cell splitting affect the Signal-to-Interference Ratio (SIR)?
It increases SIR.
What is the simplest high-speed circuit-switched data service in GSM 1800?
High Speed Circuit Switched Data (HSCSD).
Who originally started the Bluetooth project?
The Ericsson Company.
How many channels are there in the given example of spectrum allocation?
3 channels.
How are nearby base stations assigned channels to minimize interference?
They are assigned different groups of channels.
What are the typical sizes of cells in the cellular concept?
In some cities, a few hundred meters, and in the countryside, a few tens of kilometers.
What are the two types of networks defined by Bluetooth?
Piconet and scatternet.
What are the piconet secondaries synchronized with?
The primary station.
What is the defining feature of 0G in cellular network generations?
Briefcase-size mobile radio telephones.
What method does the baseband layer in Bluetooth use for access?
TDMA (Time Division Multiple Access).
What are IS-54 and IS-136?
TDMA technology in the US, compatible with AMPS.
What protocol is used for data exchange on an ACL link in Bluetooth?
Logical Link Control and Adaptation Protocol (L2CAP).
What are the key features of 5G technology?
Ultra fast internet, use of millimeter waves and unlicensed spectrum for data transmission, cloud-based network architecture, connectivity for machines and sensors, ultra fast mobile internet up to 10Gbps, low latency, total cost reduction for data, higher security, and reliable network.
How can coverage and capacity be improved in cellular systems?
Through cell splitting, sectoring, and microcells.
What is the term for the well-defined frequency band over which information is carried from sender to receiver?
Channel.
What is the main characteristic of 4G in cellular network generations?
IP-based “anytime, anywhere” voice, data, and multimedia telephony at faster data rates than 3G.
What is the core standard used in GSM 1800 or DCS 1800?
GSM.
What were the principal requirements of the 3G communication system?
Support for voice quality comparable with fixed line networks, support for both circuit-switched and packet-switched data services, support for roaming between different IMT-2000 operators, support for greater capacity and improved spectrum efficiency, and support for demanding applications.
What are the advantages of Wireless LAN (WLAN) technology?
Easy deployment, LAN extension, easy access & smart working, mobility and high productivity, cost effective.
What is the purpose of using many low power transmitters (small cells) in the cellular concept?
To cover only a small portion of the service area and increase user capacity while reducing spectral congestion.
How was the IS-95 standard modified to provide data services?
By assigning multiple orthogonal Walsh functions to a single user.
What does FCC stand for in the context of wireless communication?
Federal Communications Commission.
What are the advantages of cell structures in wireless communication?
More capacity due to frequency reuse, less transmission power needed, more robustness, and localized interference management.
What is the definition of 'Subscriber' in the context of radio terminals?
Mobile or portable user.
What is GSM?
A common TDMA technology for Europe, claiming about 3/4 of subscribers worldwide.
What are some examples of Personal Area Networks?
Wireless LAN and Bluetooth.
What are the key aspects of cellular system design fundamentals?
Frequency reuse, channel assignment strategies, handoff strategies, interference and system capacity, and approaches for improving coverage and capacity.
What are the challenges associated with poor radio coverage?
Not enough bandwidth.
Why are data services almost non-existent in first-generation (1G) cellular phone standards?
Due to incompatible standards and inefficient use of the radio spectrum.
When was the Personal Digital Cellular (PDC) system deployed in Japan?
In 1994.
What does the WLAN-MAC frame format include?
Frame control, duration of transmission (used to set the value of NAV), address fields, sequence control (sequence number in flow control), information (frame body), and frame correction (CRC 32 error detection sequence).
What does the 54-bit header field in Bluetooth frame format consist of?
A repeated 8-bit pattern.
What is the best known standard for analog cellular systems?
Advanced Mobile Phone System (AMPS).
What are the examples of devices operating in licensed bands?
TACS/NMT/AMPS/TDMA, AMPS/CDMA/TDMA, GSM/TACS/NMT, Subscriber Radio, GSM/DECT, PCS/PHS/3G.
How do all users share the spectrum in 2G CDMA?
All users share the same (large) block of spectrum, with no need for frequency planning.
What is 4G's standard for both voice and data?
An all-IP (internet protocol)-based standard.
What is the Total Access Communication System (TACS) known for?
Operating at a higher frequency and with lower bandwidth channels than AMPS.
What is the frequency range extension of TACS in the U.K. called?
ETACS.
What are the key considerations for management of wireless LAN (WLAN) connections?
Connection management, link reliability, power and link security.
What is the network used for voice over 4G?
Voice over LTE network (VoLTE) using IP packets for voice.
What are the generations covered in wireless communication systems?
2G, 3G, 4G, 5G.
What does VHF stand for?
Very High Frequency.
What is the focus of Cellular System Design Fundamentals?
Frequency reuse, channel assignment strategies, handoff strategies, interference and system capacity.
What are the key aspects of Cellular System Design Fundamentals?
Frequency reuse, channel assignment strategies, handoff strategies, interference and system capacity.
What is the characteristic of Simplex communication?
Communication in only one direction.
What is the focus of WiMAX Technology in wireless communication systems?
Broadband Wireless Access.
What is the name of the single wireless communications standard proposed by ITU for all countries in the world?
IMT-2000.
What are the generations of wireless communication systems mentioned in the syllabus?
2G, 3G, 4G, 5G.
What technologies does 5G use to improve efficiency?
Small cells and beam forming.
What is CDMA2000 1XRTT?
It is the core of the cdma2000 Standard.
What data rate was required for users moving quickly in the 3G communication system?
144 kb/s.
What are the drawbacks of Wireless LAN (WLAN) technology?
Limited Bandwidth, incompatibility, interference, less security, need backbone network.
When was 4G first defined by the ITU?
In 2008.
What are some applications of 4G?
Amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D television.
How does CDMA compare to TDMA in terms of capacity increase?
Provides 1.5-2 times capacity increase over TDMA.
What are the limitations of 2G technology in terms of data rate?
Data rate is too slow for rapid email and internet browsing applications.
What is an optional central base station called?
Access point.
When were digital cellular telephony systems of 2G deployed?
In the 1990s.
What is the purpose of cell splitting in cellular systems?
To divide a congested cell into smaller cells with their own base stations.
What organization supports Wideband CDMA (W-CDMA)?
The Third Generation Partnership Project 1 (3GPP1).
What is the duration of one timeslot in 2G TDMA?
0.577 ms.
What are the aggregate data rates of emerging wide-area wireless packet data services?
Several 100 kbps.
What are the principal requirements of 3G technology?
Support for demanding applications such as voice and data transmission, simultaneous voice and data access, multi-megabit Internet access, interactive web sessions, voice-activated calls, and multimedia content.
What are the problems associated with handoff in high-speed vehicles?
High-speed vehicles can cross many 'small' cells in a short time, leading to too many handoffs and overburden for the Mobile Switching Center (MSC).
What is the difference between Frequency Division Duplexing and Time Division Duplexing?
FDD uses two radio channels (forward and reverse), while TDD shares a single radio channel in time.
What is the main approach associated with cell splitting and cell sectoring?
Microcell Zone Concept.
What is the frequency range for IMS (802.11b/Bluetooth)?
2.4 GHz.
What standard defines the Bluetooth protocol?
IEEE 802.15.
What is the advantage of CDMA in accommodating users in the system?
There is no hard limit on the number of users that can be accommodated in the system.
What type of network is formed by Bluetooth devices spontaneously?
Ad hoc network.
What are the problems associated with the cellular concept?
The need for a fixed network for base stations, the necessity of handover, and interference with other cells.
What are the key features of 2.5G technology?
Use of existing 2G equipment, higher data rate transmission, and support for web browsing format language.
What improvements were made in the Improved Mobile Telephone System (IMTS) developed in 1960?
It included full duplex services and direct-dialing, with 23 FM channels and reduced bandwidth to 25-30 KHz.
What are the components of Broadband Wireless Access?
WiMAX Technology.
What is the focus of first-generation (1G) cellular phone standards?
Voice.
What distinguishes 2G in cellular network generations?
Digital cellular telephony.
When did the ITU propose a global frequency band in the 2000 MHz range?
In 2000.
How does 5G achieve ultra fast internet?
By using millimeter waves and unlicensed spectrum for data transmission.
What is the successor to GSM in the 3G standard?
The Universal Mobile Telecommunications System (UMTS).
When was the IMT2000 Initiative conceived?
In 1986.
What are the key components of Cellular System Design Fundamentals?
Frequency reuse, channel assignment strategies, handoff strategies, interference and system capacity.
What is the cellular concept in wireless communication?
Partitioning the region into smaller regions called cells, with each cell having at least one base station or tower.
What is General Packet Radio Service (GPRS) used for?
Packet-switched data layered on top of the circuit-switched voice.
How can the problem of 'cell dragging' be solved?
By carefully adjusting handoff thresholds and radio coverage.
What data rate was required in a low mobility or office environment in the 3G communication system?
2 Mb/s.
What is GSM in the context of 2G technology?
Global System of Mobile communications.
What is the maximum data rate of 4G?
Up to 1Gbps.
What are some examples of wireless LAN and personal area networks?
Wireless LAN, Bluetooth, and WiMAX Technology.
What is Wideband CDMA (W-CDMA) evolved from?
GSM and IS-136.
What are the three modes of transmission?
Simplex, Half Duplex, Full duplex.
What is IS-95?
A CDMA-based technology standardized in 1993, deployed in South Korea and Hong Kong in 1995, and in the US in 1996.
Why can't wireless LANs implement CSMA/CD (Carrier Sense Multiple Access with Collision Detection)?
Wireless channels cannot send data and receive collision signals simultaneously, and collision may not be detected due to the hidden station problem and signal fading.
What is the purpose of the 72-bit access code in Bluetooth frame format?
For synchronization bits and to identify the primary piconet.
What frequencies were used for cellular systems in the PCS band?
1.9 GHz.
What is the characteristic of Full-duplex communication?
Simultaneous radio transmission and reception (FDD, TDD).
What is the range of size for a Personal Area Network (PAN)?
From a few centimeters to a few meters.
What is the narrowband version of AMPS with voice channels one third the bandwidth of regular AMPS?
Narrowband AMPS (N-AMPS).
What is 'cell dragging' in the context of handoff?
It occurs when the user moves slowly away from the cell, and the tower fails to recognize it due to a strong average signal.
What is a benefit of soft handoffs in 2G CDMA?
Soft handoffs are possible.
What is the characteristic of each channel in the given example of spectrum allocation?
Each channel occupies 30kHz.
What is the arrangement for full duplex communication?
Using two different channels (front and reverse channels) or using time division in a channel.
What are some of the incompatible standards for analog cellular systems in different European countries?
Nordic Mobile Telephone (NMT) in Scandanavia, Radiocom 2000 (RC2000) in France, and C-450 in Germany and Portugal.
How are piconets combined to form a scatternet?
Piconets are combined to form a scatternet.
What are some examples of wireless communication technologies?
Wireless LAN, Bluetooth, and WiMAX Technology.
What are the technologies included in Wireless LAN and Bluetooth Technology?
Wireless LAN, Bluetooth, and Personal Area networks.
When is handoff initiated in cellular systems?
It is initiated when the mean signal over some predetermined time is below some threshold.
What is covered under Cellular System Design Fundamentals?
Frequency Reuse, channel assignment strategies, Handoff strategies, Interference and system capacity, trunking and grade off service, improving coverage and capacity – cell splitting, sectoring, microcells.
What does Cellular System Design Fundamentals include?
Frequency reuse, channel assignment strategies, handoff strategies, interference and system capacity.
What is the access method used in first-generation (1G) cellular phone standards?
FDMA (Frequency Division Multiple Access).
What is addressed in the topic of Wireless Spectrum allocation and Standards?
Wireless Spectrum allocation and Standards.
What are the examples of devices operating in unlicensed bands?
Cordless phone, remote controller, hand-held walkie-talkies, pagers, wireless LAN.
What is the characteristic of spread spectrum modulation in 2G CDMA?
Originally developed for the military and resists jamming and many kinds of interference.
Give an example of a Personal Area Network (PAN) connection.
Connection between a Bluetooth earpiece and a Smartphone.
What is the purpose of Cdma2000 1XEV-DO?
To provide high data rates (HDR) above 1 Mbps.
How much capacity increase does TDMA provide over AMPS (1G)?
3-6 times.
What is the current data rate of Bluetooth?
1 Mbps operating at 2.4-GHz bandwidth.
What is the definition of 'Mobile' in the context of radio terminals?
Any radio terminal that could be moved during operation.
How many stations can be in a piconet?
Up to 8 stations: one primary and the rest secondaries.
