Wireless/Cellular Data Network
Smartphones rely on cellular data and Wi-Fi wireless connections to stay in touch anywhere.
As cellular networks become faster and smarter, the functionality of those devices improves. By default smartphones are configured to connect to cellular service. However, if you travel, you’re probably familiar with Airplane mode. Airplane mode disables cellular but allows Wi-Fi and Bluetooth connections to continue, as they do not break airplane rules. Depending upon your phone’s operating system, you may need
to turn Bluetooth and/or Wi-Fi on manually when in Airplane mode.
2G/3G/4G/5G Smartphones are manufactured to support different versions of cellular service. The most common versions in use today are 3G, 4G, and 5G. However, some cellular services today still support 2G.
2G Global System for Mobile Communications vs. Code-Division Multiple Access 2G was the first digital cellular standard (original cellular phones were analog, subject to interference and garbled communications). 2G used two technologies initially: GlobalSystem for Mobile Communications (GSM) uses circuit switching (like landline phones) and time-sharing for multiple users.
GSM was widely used in Europe. Code Division Multiple Access (CDMA) uses packet-switching, a network technology that supports concurrent call transmitting. CDMA was widely used in North America, Japan, Korea, and Hong Kong. GSM supports simultaneous voice and data, while CDMA does not. CDMA voice quality is typically better than GSM. Originally, the choice between GSM or CDMA was made by the cellular provider, but more recent 2G phones support either standard. GSM phones use interchangeable SIM cards for easy switching between carriers, while CDMA phones don’t. Both GSM and CDMA versions of 2G have been phased out by most wireless carriers worldwide and in the United States.
3G Cellular Service 3G, unlike 2G, was designed for data networking from the ground up, using packet-switching technology. There have been a number of 3G cellular networks using different technology, including CDMA 2000 (an improved version of CDMA), Universal Mobile Telecommunications System (UMTS), and EDGE.
3G networks support web browsing, web-enabled apps, video calling, and GPS navigation. 3G has a peak speed of about 2Mbps. By the end of 2022, 3G support was phased out by all U.S.-based cellular carriers. 3G support is also in the process of being phased out by other countries.
4G Cellular Service 4G cellular service is the mainstream cellular service in the United States and most other nations as this book goes to press. Compared to 3G, 4G runs at much faster speeds. The most common version of 4G in the USA is Long Term Evolution (LTE), which made it easier for networks originally using GSM and CDMA to move to 4G.
LTE is sometimes referred to as “true 4G” because it is much faster than HSPA+, which is an update to 3G technology sometimes marketed as 4G. Both LTE and HSPA+ support multiple input-multiple output (MIMO) antennas to improve transmission and receiving speed and reliability.
5G Cellular Service 5G cellular service is far and away the fastest cellular service available and can also be used as a replacement for wired broadband service. 5G networks use a cellular technology called New Radio (NR), which supports both 4G and 5G signals. Thus, unlike earlier transitions that saw 2G and 3G networks shut down to allow cellular frequencies and physical infrastructure to be repurposed for faster cellular networks, 4G will continue to work alongside 5G.
5G uses a large number of frequencies that offer different balances between speed and range. As with Wi-Fi and other radio frequencies, faster frequencies have shorter ranges, and slower frequencies have longer ranges.
Hotspot
If you are unable to connect your computer or tablet to a Wi-Fi network, you can still get online by using your smartphone’s mobile hotspot feature, sometimes called mobile hotspot and tethering. To get started, locate the mobile hotspot feature in your smartphone. Typically, it is part of the Connections or Wi-Fi dialog (Figure 4.3). Normally, this option turns your phone into a Wi-Fi hotspot. However, depending upon your smartphone and your carrier, you might be able to use Bluetooth.
Enable Bluetooth
The first step in using Bluetooth is to turn it on in your smartphone or tablet.
On a device running iOS or iPadOS, do the following:
1. Tap Settings.
2. Tap Bluetooth.
3. Drag Bluetooth to On.
On a device running Android (based on Samsung A20 running Android 11), do the
following:
1. Tap Settings.
2. Tap Connections.
3. Drag Bluetooth to On.
Enable Pairing
The next step is to enable pairing, the process of enabling your smartphone or tablet to
“see” another Bluetooth device.
1. The smartphone or tablet starts scanning for devices automatically as soon as you turn on Bluetooth.
2. On iOS or iPadOS, the devices you can connect to are listed under Other Devices. On Android, devices you can connect to are listed under Available Devices.
Find a Device for Pairing
The next step is to select a device to pair with.
On a device running iOS or iPadOS, do the following:
1. Detected devices that are not yet paired are listed in Other Devices.
2. Tap the device to add it to My Devices
On a device running Android:
1. Detected devices that are not yet paired are listed as Available Devices.
2. Tap the device to add it to Paired Devices.
Enter the Appropriate PIN Code
If you need to enter a PIN code, follow the instructions on-screen
When the pairing process is complete, the device is listed in the My Devices category on iOS or the Paired Devices category on Android.
Test Connectivity
Test the device for functionality. Check music playback, typing, or other functionalitys needed.
Disconnecting Before the device can be used with a different computer or mobile device, it must be disconnected
from the original host device. The easiest way to do this is to turn off Bluetooth on the host device.
LOCATION SERVICES
Smartphones and cellular-enabled
tablets have two location services: one based on GPS
and one based on cellular. The following sections discuss the differences between them.
Global Positioning System Services
The Global Positioning System (GPS) uses signals received from satellites to determine the
position of the GPS receiver. Smartphones include GPS receivers that are used by Google
Maps, MapQuest, Apple Maps, and other mapping software.
To configure GPS services on Android, open Settings and tap Location. When Location
is On, GPS services are available to mapping and other apps. When Location is Off, GPS
services and Wi-Fi
and Bluetooth services to improve accuracy are not available
