Comm 280 PSU Exam 2

CDMA

Code-division multiple access: A conversation is broken down into individual packets, each stamped with an identity code and sent out over a spread spectrum of frequencies. "Multiple classes can be taught in the same classroom at the same time. You only "hear" your intended class and have the ability to filter out the noise from other classes."

Channel

The pair of transmit signals (base station and mobile device) form the channel

Development Vacuum (3G to 4G Consideration)

The success of the iPhone liberated handset manufacturers to develop new features, with limited carrier input. For example "FaceTime" overwhelmed ATT

No Coverage Gaps

The use of a hexagon grid structure allowed carriers to provide seamless coverage and minimize dropped calls

4W Connection

To support long distance connections, signal amplifiers were needed. As a result, two wires were allocated for each direction, thereby creating a four-wire (4W) connection.

Control Channel

Only carries cellular system data. Primarily responsible for call setup. There is a forward and reverse control path between the base station and handset to set up the call.

OFDMA

Orthogonal Frequency Division Multiple Access: Uses two-dimensional resource scheduling (in time and frequency) to dedicate an overlapping but non-interfering frequency range to each user so that multiple users can be supported in the same time slot. Both LTE and WiMAX utilize OFDMA technology.

Media Gateway Control Protocol

A signaling and control protocol for VoIP sessions

Advanced Antenna Techniques (LTE Advanced)

Adding antennas to MIMO configuration to increase data rates and capacity. The 3GPP standard has approved 8x8 MIMO configurations (have fun antenna team)

Minimize/Reduce Interference

By utilizing non-adjacent cells, frequency interference was minimized

Carrier (channel) Aggression (LTE Advanced)

Enables a network operator to combine up to 5 channels (up to 20 MHz each) to create a 100 MHz channel, thereby creating faster data rates. Network operators generally don't posses 100 MHz channels therefore channel aggression is needed to achieve faster rates

Class 4 (TSH)

For calls between two local exchanges who aren't directly connected

FDMA

Frequency-division multiple access: Conversation is transmitted over a dedicated frequency for each direction. "A classroom is dedicated for one class. No other classes are taught in that classroom."

Tier-1 Carriers - A 4G View

In terms of 4G Verizon is the most aggressive in the U.S. AT&T and T-Mobile marketed HSPA+ as 4G until LTE. While carriers have marketed 4G as 4G LTE, the tech standard is named 3G LTE

Earphone (Receiver)

Receives electrical signal produced by the transmitter. The varying levels of electricity produce varying levels of magnetism. The magnetic variance causes the diaphragm to produce sound that corresponds to the transmitter

Mobile Device

Receives signal base station signal and transmits from 824 MHz to 849 MHz

Wireless Spectrum

Spectrum is a fundamental element of wireless service. A carrier spectrum position will have an impact on their network technology, number of subscribers, and ability to introduce new products and services.

SID

System Identification Code: This is a unique 5-digit number that is assigned to each carrier by the FCC.

Half Duplex/Full Duplex/Multiplex

Telecommunications networks evolved to provide more robust capabilities for consumers. Tech advancements led to higher consumer adaptation and usage

Propagation Delay (Transition Impairment)

The actual time it takes for a signal to travel long distances causes a noticeable delay from transmitter to receiver

Geography (Voice network limitations)

The concepts of LATA, Local loop, and the Telephone Switch Hierarchy didn't align well with the global reach of the internet.

Spectrum Conversation and Frequency Reuse

The initial FCC spectrum allocation, bandwidth requirements, and ultimate desire to provide nationwide coverage placed a premium on spectrum conversation. As such, wireless carriers deployed network configurations that allowed them to reuse frequencies (similar to fiber-optics)

Class 5 (TSH)

The local exchange or end office that serves as the connection point to the customer and provides the dial tone

Bandwidth (Voice network limitation)

The maximum data rate for an analog network is 33.6 Kbps (56 Kbps modems utilized DSL connections at the ISP). Can't handle images/videos.

Impedance (Transition Impairment)

The measure of total opposition that a circuit presents when an Altering Current (AC) is applied

Attenuation (Transition Impairment)

The signal quality diminishes over long distances

Transition from Digital (2G) to 3G

The transition from 2G to 3G brought broadband capabilities (4 Mbps download, 1 Mbps upload) speeds to wireless networks. -RIM Blackberry: revolutionized mobile email with triple BES encryption -3G Wireless Access Card: cards were inserted into laptops to deliver broadband speeds

TDMA

Time-division multiple access: Each conversation is broken down into packets, which are sent sequentially, along with other conversations, over a single selected frequency. "A classroom is used for a specific period of time, when done another class may be there"

TCP/IP

Transmission Control Protocol/Internet Protocol

IP Telephony

Two devices that natively support IP and therefore transmit data packets directly

Trunk Line

connection point between equipment (not homes)

Inter eXchange Carrier (IXC)

provides connection to a different LATA (long distance carriers)

Local Loop

the physical link from the customer to the carrier (AKA "Last Mile")

International Numbering

| International Prefix | Country Code | Trunk (Area) Code | Subscriber Number |

P.O.P.

Point of presence (a connection point)

4 Basic Elements to International Calls (to/from landline)

-011 (dialing out from the US) -Country Code -City code -City number

First Wireless Handset

-1973, Motorola employee Martin Cooper made first handset call to Bell Laboratories -Prototype called "DynaTAC" (DYNamic Adaptive Total Area Coverage) -9 in. tall -2.5 lbs. -30 circuit boards -35 min. talk time -10 hour recharge time

Wireless Transition from Analog to Digital

-1995, FCC holds PCS (personal communication services) spectrum auctions. PCS operated in the 1900 MHz band. Cellular operated in 800 MHz -Sprint PCS: "Clear alternative to cellular"+"hear a pin-drop" campaign -Motorola invents MIRS to convert analog dispatch systems to digital services. Becomes iDEN (Integrated Dispatch Enhanced Network) -1991 O'Brien obtains a waiver from FCC to use the new technology to integrate his SMR license. Fleet Call is born, renamed Nextel

3 Basic Elements to a call placed in the US

-3 digit area code -3 digit exchange -4 digit subscriber number

Voice Network Limitations

-Bandwith -Traffic patterns -Geography

Elements of a Basic Telephone

-Converts human sounds into electrical signals over wires (historically). -Microphone (Transmitter) -Earphone (Receiver) -The telephone is connected to a PTSN

Common Migration Strategies

-Handset promotions: offer price discounts on the new handsets that operate on the new network -New products: can sometimes entice subscribers to upgrade their handset and renew their contract (with new terms) -Bundled packages: smartphones with required data plans made bundled family plans appealing and cost effective for many consumers

Ramifications of operating different technologies (Tier-1 Carriers)

-Lack of device portability -Diminished purchasing power -Limited innovation-3 platforms -Vendor frustration -International roaming limitations -Confused European carriers-they all selected GSM

Unique VoLTE Products (Verizon new offerings)

-Lower Power Consumption (potential 40%) -Interactive Services: voice is treated like any other data application and consumes little bandwidth, additional data traffic (messaging, video) can be sent to utilize available bandwidth -HD Voice: Best voice quality available, rival landline -Video Calling: Start video directly from contacts (FaceTime: can you hear me?) -Call Switching: Instantly switch from only voice call to voice and video call

Cellular Network Elements

-MTSO -MSC -Control Channel -Voice Channel

Multiplex

-Multi-way communication -Multiple transmits and receipts on the same wire -Simultaneous talking/listening across multiple parties, concurrently

Half Duplex

-One-way communication -Walkie Talkie -Push-to-talk, release to listen

VoIP Use Cases

-PC-to-PC -PC-to-Telephone (Analog or IP) -Telephone-to-Telephone (Analog or IP)

Transition Impairments That Can Occur During a Phone Conversation

-Propagation Delay -Attenuation -Impedance -Talker/Listener Echo

VoIP Benefits

-Save Money: reduces local and long distance charges due to IP delivery of signal (vs. PSTN) -Simplified Network: One network for voice and data communications -Scalability: Simple to add/remove devices to the network -Portability: Easy to take phone system's features with you -Global: Your ability to communicate is no longer constrained by geography

Why was SMS so successful?

-Simplicity: easy to send/receive texts (140-160 characters -Ubiquitous: all data-capable handsets support messaging, send messages to anyone -Native: Users didn't have to download anything. Devices support texting out of the box.

Wireless Early Considerations

-Spectrum -Network -Authentication -Handoffs -Roaming

Full Duplex

-Two-way communication -Transmit and receive -Simultaneous talking/listening

VoIP Limitations

-Voice quality -Power requirement (Non-cordless landlines don't need power) -911 no native E-911 due to global culture -National Security

2015 FCC Definition of Broadband

25 Mbps for downloads, 3 Mbps for uploads

Modem

A combination of MODulator and DEModulator

Device Types (3G to 4G Considerations)

Apple followed up the iPhone with another successful product launch-iPad

Range of Cell Tower

Approximately 10 miles

Migrating Subscribers

Can be a tricky proposition. A postpaid (contract) subscriber cannot be forced to sign a new agreement (hello unlimited data subscribers). Therefore deploying a new 4G network with new 4G-enabled smartphones requires a delicate balance.

C.O.

Central Office (a switching point)

The Local Loop

Connecting a telephone to a local exchange. The local loop is a two-wire (2W) circuit that carries signals in both transmission directions (transmit/receive)

Demodulator

Converts the analog data into digital data so it can be received by the computer

Modulator

Converts the digital data into sounds prior to transport over the analog voice network

ESN

Electronic Serial Number: This is a unique 32-bit number that is programmed into the phone when manufactured Only permanent number

Video (3G to 4G Consideration)

Emerged as the preferred content type. The large, consumer generated video files also proved to be troubling for carriers.

LTE and WiMAX

Emerged as two possible 4G technologies. While AT&T and T-Mobile initially marketed their HSPA+ networks as 4G, the reality was that the underlying network technology was still 3G (until they deployed LTE)

Telephone Switch Hierachy

In an attempt to improve network performance and provide economies of scale, a Telephone Switch Hierarchy was developed with 5 classes

Microcell

Intended to augment the macrocell with a range that is limited to a single building or city block

Macrocell

Intended to provide largest coverage area, and will have largest power requirement. Range is 1-30 km with an antenna at the top of a tall building

ITU

International Telecom Union. Defines international telephone number formats.

LATA

Local Access and Transport Area

LTE

Long Term Evolution: LTE became the technology standard developed by the 3GPP, a GSM standards group.

MIN

Mobile Identification Number: The 10 digit phone number that is assigned to you (or brought from a previous carrier)

MSC

Mobile Switching Center. Responsible for routing the mobile calls (mobile to mobile and mobile to landline). Billing information is typically captured by MSC.

MTSO

Mobile Telephone Switching Office. Behaves similar to the Central Office in a PSTN. As such, the MTSO is the heart of the cellular network.

Microphone (Transmitter)

Moveable speaker diaphragm that is sensitive to amplitude and frequency. Converts human voice and sends analog electrical signals out into the voice network

MIMO

Multiple Input, Multiple Output

NANP

North American Numbering Plan. Defines domestic telephone number formats. Serves 20 North American countries including the U.S. and its territories, Canada, and many others, but not Mexico.

Voice Channel

Paired frequencies that handle the call traffic (voice and data). Similar to the control channel, the voice channel has a forward and reverse path.

Class 1 (TSH)

Primarily a connection point for international calls

Class 3 (TSH)

Primarily used for calls outside the geographical boundary of class 4 connections

Class 2 (TSH)

Primarily used for interstate and/or long distance calls

Base Station (Cell site)

Provides a wireless signal by utilizing a transceiver and antenna. The base station transmits/receives wireless signals for a carrier. Base stations operate from 869 MHz to 894 MHz.

Femtocell

Provides the smallest coverage area. Typically installed by the end user and primarily viewed as an in-home coverage enhancing solution

PTSN

Public Switched Telecommunications Network. The telephone is connected to a PTSN for local, national, and international voice communication. The connection to the PTSN may be via a Local Exchange Carrier (LEC).

RTP

Real-Time Transport Protocol. Sends voice packets for VoIP sessions

SIP

Session Initiation Protocol. The protocol used for VoIP sessions

The Original Killer App-SMS

Short Message Service: No wireless product had a greater impact on data adaptation (and revenue)

Picocell

Small coverage area that typically supports up to 100 concurrent users

Screen Sizes (3G to 4G Consideration)

Smartphone screen sizes increased, generating larger photo and video files, often uploaded to social media sites

From 3G to 4G

Smartphones quickly overwhelmed carrier 3G networks. As a result, carriers worked hard to upgrade their networks to accommodate the distribution demand for photos and video.

VoIP

Voice over Internet Protocol. Facilitates the transmission of digitalized voice over an IP Network

VoLTE

Voice over LTE: Routing voice traffic over an IP network, similar to VoIP but with a mobility element. Goal was to improve voice quality. -Scalable/reliable: Placing a voice call is still the central element of user experience (and carrier revenue). Essential for a carrier to offer high quality voice experience to millions of users -Efficient: Migrating voice traffic to LTE was more efficient for carriers (most voice traffic was still 3G or even 2G)

Traffic Patterns (Voice network limitations)

Voice traffic tended to be symmetrical (full duplex conversation). Voice demanded traffic patterns were fairly consistent and easy to predict (daytime vs. nighttime usage). Conversely, internet traffic was asymmetrical, with somewhat unpredictable patterns and a bust of demand. Think Netflix binge watching.

Talker/Listener Echo (Transition Impairment)

When a reflection occurs during transmit or receiver functions

LTE Advanced

While VoLTE is realistically an addition to 4G, LTE Advanced represents a significant step for the wireless industry, similar to the jump from 3G to 4G

The Promise of 4G

With the convergence to one technology (OFDMA), 4G holds the promise to break free from the multitude of constraints that existed in the 2G/3G environments.

VoIP Overview

With the growth of internet adoption and increasing data speeds, entrepreneurs began to investigate how to leverage the boundless nature of the internet to facilitate voice communication.

WiMAX

Worldwide Interoperability for Microwave Access. WiMAX became the technology standard developed by IEEE (802.16e) and the WiMAX Forum.

Carrier Wave

an electromagnetic wave that can be modulated as in frequency, amplitude, or phase, to transmit speech, music, images, or other signals