A+ Core 1

Twisted Nematic (TN) LCD

- The original LCD technology - fast response times (gaming) - Poor viewing angles - color shifts

Corporate Email Configuration

- User does not need to configure anything - The MDM makes the changes on the device - Account details, server address, communication method

Connecting mobile devices

- Wired and wireless - Used for synchronization, connectivity, back, and identification

Long Term Evolution (LTE)

- a 4G technology - converged standard (GSM and CDMA providers) - based on GSM and EDGE (Enhanced Data Rates for GSM Evolution) - Standard supports download rates of 150 Mbit/s

Vertical Alignment (VA) LCD

- a good compromise between TN and IPS - good color representation - slower response times than TN

TCP and UDP

- boxes that are holding data - transported inside of IP (encapsulated by the IP protocol)

User Datagram Protocol (UDP)

- connectionless - no formal open/close to the connection - unreliable delivery - no error recovery, no reordering of data or retransmissions - no flow control - sender determines the amount of data transported

In Plane Switching (IPS) LCD

- excellent color representation - more expensive to make than TN

CCFL (cold cathode fluorescent lamp)

- fluorescent lamp - higher voltage and power needed - added thickness to display - no longer a common backlight - older laptops use these

Network

- functions like a road - Ethernet, DSL, cable

Internet Protocol (IP)

- functions like a truck

Universal Serial Bus (USB)

- high-speed wired communication; used for charging and data transfers • simplify connections - printers, storage devices, keyboard, mouse

802.11

- local area network (LAN) - High Speed - Internet access

Speaker

- mobile audio - battery powdered - wireless connection - bluetooth link - stereo sound - small package

Backlight

- needed in LCD displays (florescent lamp/LED to LCD display to your eyes)

Solid State Drive (SSD)

- newer, no moving parts -all memory -silent, fast access time, less latency -2.5 inch form factors

NFC

- send small amounts of data wirelessly over a limited area - built into your phone (i.e. payment systems, transporatation, in person information exchange - access token, identity "card", short range with encryption support

M2

- smaller form factor - more storage - no SATA data or power cables - easy to install and replace

Application Information

- things inside the boxes

Mini-USB

- used by older devices; slightly larger than micro-USB

NetBIOS Name Service Port

udp/137

Simple Network Management Protocol (SNMP) Query Port

udp/161

Domain Name System (DNS) Port

udp/53, tcp/53

Dynamic Host Configuration Protocol (DHCP) Port

udp/67, udp/68

Laptop batteries

• The power source when unplugged - May be easily replaced or require a tear down - Five minutes vs. one hour

Touch pens

• Touchscreen pen / touch screen stylus / capacitive stylus - Activate the interface without actually touching it • Handwriting - Note taking, signatures • Precise selection - Easier to see the screen

Hotspot

• Turn your phone into a WiFi hotspot • Your own personal wireless router • Extend the cellular data network to all of your devices • Dependent on phone type and provider • May require additional charges and data costs

Digitizer

• Use a pen-like device as input - Useful for graphical input • Becoming more common on laptop / tablets / hybrids

Drawing pad

• Use an active stylus with an external digitizer - Very precise input

docking station

• Use external keyboard and mouse • Extend existing laptop interfaces • Add additional functionality • Desktop adapter cards • Avoid cable issues

liquid crystal display (LCD)

A flat-panel monitor that creates an image when liquid crystals become electronically charged.

Multiplexing

A form of transmission that allows multiple signals to travel simultaneously over one medium. - use many different applications at the same time - TCP and UDP

Post Office Protocol version 3 (POP3) Port

tcp/110

NetBIOS Session Service Port

tcp/139

Internet Message Access Protocol version 4 (IMAP4) Port

tcp/143

File Transfer Protocol (FTP) Port

tcp/20, tcp/21

Secure Shell (SSH) Port

tcp/22

Telecommunication Network (Telnet) Port

tcp/23

Simple Mail Transfer Protocol (SMTP) Port

tcp/25

Hypertex Transfer Protocol Secure (HTTPS) Port

tcp/443

Server Message Block (SMB) Port

tcp/445

Hypertext Transfer Protocol (HTTP) Port

tcp/80

Global Positioning System (GPS)

* created by the US Department of Defense - over 30 satellites currently in orbit * Precise navigation - need to see at least 4 satellites *determine location based on timing differences - longitude, latitude, altitude * Mobile device location services and geotracking - maps - determine physical location based on GPS, WIFI, and cell towers

3G Technology

*3rd Generation • Introduced in 1998 *Upgraded data connectivity over 2G • Incremental 3G updates improved speeds • Usually several megabits per second *Bandwidth improvement allowed new functionality • GPS • Mobile television • Video on demand • Video conferencing

Corporate applications

- Allow or restrict app installation - Prevent unauthorized app usage

2G Networks

- GSM (Global System for Mobile Communications) - CDMA (Code Division Multiple Access)

Global System for Mobile Communications (GSM)

- Mobile networking standard • 90% of the market - Originally an EU standard - Worldwide coverage • Used by AT&T and T-Mobile in the United States - Move your SIM card (Subscriber Identity Module) from phone to phone • Original GSM standard used multiplexing - Everyone gets a little slice of time

Organic light emitting diode (OLED)

- Organic compound emits light when receiving an electric current • Thinner and lighter - Flexible and mobile - no glass needed • No backlight - The organic compound provides the light • Laptops, phones, smart watches - Very accurate color representation - A bit higher cost than LCD

Two-factor authentication

- Require specific authentication types - Biometrics, pseudo-random authentication app

IPv4 sockets

- Server IP address, protocol, server application port number. -Client IP address, protocol, client port number.

Transmission Control Protocol (TCP)

-A connection-oriented protocol -There is a formal process when starting and ending the connection -A reliable form of delivery -Can recover from errors and can re-transmit the data -Can manage out-of-order message or retransmissions -There is Flow Control where the receiver can manage how much data is sent (slow or speed things up) -Station A acknowledges received data (ACK) from Station B -Data is resent if Station A does not receive an ACK from Station B

Micro-USB

-A smaller USB connection -Common now worldwide

LED-backlit LCD display

-Backlight is LEDs instead of florescent -LED's are either placed around the edge of the screen OR in an array (matrix) behind the screen -The latest laptops are LED-backlit -Uses same DC voltage (no voltage conversion is needed) -If display stops working, look closely (use a flashlight) to still see information on the screen -Inverter or whole display will need to be replaced

Non-ephemeral ports

-Permanent port numbers -Ports 0 through 1,023 -Usually on a server or service

Bluetooth

-Personal area network (PAN) - short range - connect peripherals and other nearby devices • Remove the wires - Headsets, speakers, keyboards/mice • Uses the 2.4 GHz range - unlicensed ISM (Industrial, Scientific and Medical) band - same as 802.11 • Short-range - most consumer devices operate to about 10 meters - Industrial ___ devices can communicate over 100 meters • High speed communication over short distances • PAN (Personal Area Network) • Connects our mobile devices • Smartphones • Tethering • Headsets and headphones • Health monitors • Automobile and phone integration • Smartwatches • External speakers

Laptop memory

-Small Outline Dual In-line Memory Module (SO-DIMM) - increase memory, normally used in laptops and mobile devices; easy to replace -Laptop memory soldered to the system board cannot be upgraded

Ephemeral ports

-Temporary port numbers -Ports 1,024 through 65,535 -Determined in real-time by the client

Laptop Storage

-magnetic disk -SSD -M2

Bluetooth Pairing

1) Connect a bluetooth device 2) Pair the devices one time

Bluetooth Pairing Process

1) Enable bluetooth on both devices 2) Set devices to discoverable mode 3) Select discovered device 4) Enter or confirm PIN 5) Test connectivity

Steps to upgrade HDD to SSD

1) Install OS on the SSD 2) Image/clone the HDD 3) Imaging software needed 4) Create an image file 5) Drive-to-drive image

Disadvantages of LCD

Black levels are a challenge Requires separate backlight Lights are difficult to replace

Laptop Display Components

LCD, OLED, Wi-Fi antennas, webcam, microphone, backlighting, digitizer, inverter, touchscreen

LTE Advanced (LTE-A)

Standard supports download rates of 300 Mbit/s

Mobile Device Accessories

Touch pens, active stylus, drawing pad, trackpad, external options, drag and tap, enable and disable, headsets, speakers, camera/webcam, docking station, port replicator

OSI Layer 4

Transport Layer

Inverter

Turn DC into AC

Connectors for Mobile Devices

USB, USB-C, Lightning, Serial Interfaces, NFC, Bluetooth, Hotspot

Webcam

a video capture device connected to a computer - usually includes both audio and video

Mobile Device Connectivity

bluetooth, GPS, MDM

Microphone

built-in to the laptop display

Wireless network connectivity

connection with no wires

Computer

has to take some kind of input, does some processing and storage and provides an input

Advantages of LCD

lightweight, relatively low power, relatively inexpensive

Port numbers used by TCP/UDP

number between 0 and 65,535 - for communication and NOT security - TCP port numbers aren't the same as UDP port numbers

Magnetic Disk

older, hard drives - traditional spinning drive platters -2.5 form factors (3.5 inch for desktops)

Biometrics

sign in or unlock your laptop with a fingerprint or face recognition (something you are); relatively secure; requires additional configuration in the OS

USB-C

• 24-pin double-sided USB connector • Used for both hosts and devices • Acts as a USB 3.1 / USB 2.0 / USB 3.0 / USB 4 connection • different signals can use the same connector - can transmit other signals (DisplayPort, HDMI, Thunderbolt) • replaces all the other USBs - one connector to rule them all • describes the physical connector - it doesn't describe the signal

Lightning

• Apple proprietary • 8-pin digital signals • iPhone, iPad, iPod devices • Some advantages over Micro-USB • Higher power output for phones and tablets • Can be inserted either way • Simpler design, more durable

Communication using TCP

• Connection-oriented protocols prefer a "return receipt" - HTTPS (Hypertext Transfer Protocol Secure) - SSH (Secure Shell) • The application doesn't worry about out of order frames or missing data - TCP handles all of the communication overhead - The application has one job

MDM configurations

• Corporate email configuration • Two-factor authentication • Corporate applications

Serial Interfaces

• DB-9 - also called DE-9 • Commonly used for RS-232 signals - Recommended Standard 232 - An industry standard since 1969 • Serial communications standard - Traditionally used for modem connections • Now used as a configuration port - Switches, routers, firewalls, etc - Use a USB to DB-9 converter cable

Active stylus

• Digital stylus - A more advanced writing tool • The stylus communicates directly to the device - Pressure sensitivity, programmable buttons, etc. • Must be compatible with the tablet - e.g., Apple iPad uses an Apple Pencil

Laptop hardware

• Engineered to precise specifications - A challenging repair • Some laptops are easier to fix than others - An ongoing learning process • Understand the process - The details will vary between laptop manufacturers ITEMS: - batteries, keyboard, keys, memory, storage, 802.11 wireless and bluetooth, biometrics, NFC

Code Division Multiple Access (CDMA)

• Everyone communicates at the same time • Each call uses a different code • The codes are used to filter each call on the receiving side • Used by Verizon and Sprint • Handsets are controlled by the network provider • Not much adoption elsewhere

5G

• Fifth generation cellular networking - Launched worldwide in 2020 • Significant performance improvements - At higher frequencies - Eventually 10 gigabits per second - Slower speeds from 100-900 Mbit/s • Significant IoT impact - Bandwidth becomes less of a constraint - Larger data transfers - Faster monitoring and notification - Additional cloud processing

Headsets

• Hands-free audio • Wired - Connects to 3.55 mm TRRS (tip-ring-ring-sleeve) connector; Analog audio jack; iPhone can use Lightning Port • Wireless - Uses Bluetooth

Thunderbolt

• High-speed serial connector - Data and power on the same cable - Based on Mini DisplayPort (MDP) standard • Thunderbolt v3 • 40 Gbit/s aggregated throughput • USB-C connector

Camera / webcam

• Internal or external - Commonly external on desktops, internal on laptops/tablets/phones • Accessible from multimedia applications, photo utilities,and video conferencing - Real-time video communication

Mobile Device Management (MDM)

• Manage company-owned and user-owned mobile devices • BYOD - Bring Your Own Device • Centralized management of the mobile devices • Specialized functionality • Set policies on apps, data, camera, etc. • Control the entire remote device or a "partition" • Manage access control • Force screen locks and PINs on these single user devices

Touchscreen

• Merge laptop and tablet input • No keyboard required, but often still available • Many options for input - Use the best one for the job

Cellular Networks

• Mobile devices • "Cell" phones • Separate land into "cells" • Antenna coverages a cell with certain frequencies • Poor data support • Originally used circuit-switching • Minor upgrades for some packet-switching

Wi-Fi antennas

• Multiple antennas - WiFi main and aux and Bluetooth • Antenna wires wrap around the laptop screen

Why would you ever use UDP?

• Real-time communication (phone call) - There's no way to stop and resend the data - Time doesn't stop for your network • Connectionless protocols - DHCP (Dynamic Host Configuration Protocol) - TFTP (Trivial File Transfer Protocol)

Trackpad

• Replace the mouse - Useful in tight working areas - Common on laptops • External options - Battery powered - Bluetooth connected • Drag and tap - Or use multiple finger input for right-clicking, zooming, and window control • Enable and disable - Avoid inadvertent mouse clicks and movements

Near Field Communication (NFC)

• Short-distance networking - 4 centimeters or less - Data transfers or authentication • Common on mobile phones and smart watches - Payment method on your wrist • Use it for authentication without typing a password - Hospital workstations, warehouses, manufacturing • Two-way wireless communication - Builds on RFID, which is mostly one way • Bootstrap for other wireless - NFC helps with bluetooth pairing • Access token, identity "card" - short range with encryption support

port replicator

• Similar to a docking station • Does not have an expansion card option • Usually connects using USB

Laptop keys

• Some repairs might require the removal or replacement of a key cap - This can be a delicate procedure • Check with the manufacturer's instructions - It's very easy to accidentally break the key cap or the components underneath

Speedy Delivery

• The IP delivery truck delivers from one (IP) address to another (IP) address • Every house has an address, every computer has an IP address • Boxes arrive at the house / IP address • Where do the boxes go? • Each box has a room name • Port is written on the outside of the box (what app is gonna receive this data) • Drop the box into the right room

Laptop Keyboard

• The most-used component of the laptop - Can be easy to replace - A few screws and a single ribbon cable - May not always be this simple • Or connect an external USB keyboard Not very portable, but works in a pinch