What is the difference between Wi-Fi and cellular? When would you use one versus the other?

Wi-Fi is a LAN, which uses radio waves of 2.4 GHz UHF and 5 GHZ. Wi-Fi is location-based which covers a small area such as your home, office, café, hospital, or any other business. Speed can be much faster than cellular, and there are no data limits. In order to have Wi-Fi connection, a device must have a wireless adapter that translates between data and radio signals. The device communicates with the adapter’s chip using a protocol such as UART or SPI. The adapter then communicates with an external router, which sends this data to the Internet via a wired Ethernet connection (Spofford, 2019, para. 5).

Cellular if offered by large mobile telecommunications companies such as Verizon and AT&T, covers larger areas than Wi-Fi. Cellular uses cell towers to connect devices. Two of the most popular modern cellular IoT technologies are LTE-M (Long-Term Evolution for Machines) and NB-IoT (Narrowband IoT). LTE-M is faster and is compatible with the existing LTE infrastructure. On the other hand, NB-IoT requires cellular providers to upgrade their hardware, which is why its rollout has been slower than LTE-M so far. NB-IoT also has a wider range than LTE-M, but requires the device to be stationary (Spofford, 2019, para. 8).

Many mobile devices have the ability to connect to Wi-Fi and Cellular if one connection is weaker than the other many devices can or will switch to the best connection. In order to save your cellular data connecting to a Wi-Fi would be an option.

Reference

Spofford, D. (2019, August 6). Wi-Fi vs. Cellular: Which is Better for IoT? Retrieved from https://www.verypossible.com/blog/wi-fi-vs-cellular-which-is-better-for-iot

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Hi all,

A local area network (LAN) is a connection of computers and devices on a network and usually confined within a school, hospital, courthouse, police, etc. (Singh, 2019, Para. 3). Some advantages of a Lan are the ability to share information, applications, centralized data, data security, and internet sharing. The disadvantages are high startup cost, privacy violations from administrators, maintenance of the LAN, and limited area coverage.

A metropolitan area network (MAN) is a system that covers a larger area by connections LANs to a larger network of computers. In the Metropolitan area network, various Local area networks are connected through telephone lines. The size of the Metropolitan area network is larger than LANs and smaller than WANs (wide area networks), a MANs covers the larger area of a city or town (Singh, 2019, Para. 4). Advantages of a MAN is that it is less expensive to attach MAN to a WAN, many use fiber so data speeds can reach up to 1000 Mbps, multiple users can get the same speeds, and is more secure than a wide area network. The disadvantages are that MAN’s are difficult to manage if the size increases, highly qualified IT security staff is needed to prevent hacking, more technical IT professionals are required to set up the network, and the cost of fiber optic cables for the network is expensive.

A wide area network (WAN) provides long-distance transmission of data. The size of the WAN is larger than LAN and MAN. A WAN can cover a country, continent, or even a whole world. Internet connection is an example of WAN. Other examples of WAN are mobile broadband connections such as 3G, 4G etc. (Singh, 2019, Para. 3). Some advantages of a WAN are larger cover area, ease of sharing information, files, applications, resources, supports global markets, and business. Disadvantages are a higher cost of investment at the start, prone to more errors, difficult to maintain, and pose a higher risk in security.

 

Thank you,

 

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Describe the functions of a hub, bridge, switch, and router.  Discuss the differences between the devices.   

A hub a very basic network device that connects all the computers in a network. It sends all the network data to all the computers connected to it, without using any intelligence of its own. Each port on the hub is on the same network segment. Thus, a hub has one segment and one collision domain. The job of a hub is simply sending out anything that comes to it to other computers connected to it (Test King, n.d., para. 3).

In the physical world, a bridge connects roads on separate sides of a river or railroad tracks. In the technical world, bridges connect two physical network segments. Each network bridge keeps track of the MAC addresses on the network attached to each of its interfaces. When network traffic arrives at the bridge and its target address is local to that side of the bridge, the bridge filters that Ethernet frame, so it stays on the local side of the bridge only (Simoneau, 2017, para. 4).

Specifically, switches greatly improve network performance compared to hubs, by providing dedicated bandwidth to each end device, supporting full-duplex connectivity, utilizing the MAC address table to make forwarding decisions, and utilizing ASICs and CAM tables to increase the rate at which frames can be processed (Simoneau, 2017, para. 7).

A router is a device like a switch that routes data packets based on their IP addresses. Router is mainly a Network Layer device. Routers normally connect LANs and WANs together and have a dynamically updating routing table based on which they make decisions on routing the data packets. Router divide broadcast domains of hosts connected through it (GeeksforGeeks, 2019, para. .7).

All these devices provide a connection from one device(s) to another across a network. How they perform is what sets them apart from each other.

 

Thank you,

David

References

Geekfor Geeks. (2019, October 1). Network Devices (Hub, Repeater, Bridge, Switch, Router, Gateways and Brouter). Retrieved from https://www.geeksforgeeks.org/network-devices-hub-repeater-bridge-switch-router-gateways/

Simoneau, P. (2017, July 30). What's the Difference Between Hubs, Switches & Bridges? Retrieved from https://www.globalknowledge.com/us-en/resources/resource-library/articles/what-s-the-difference-between-hubs-switches-bridges/

Test-King. (n.d.). Describe the purpose and functions of various network devices. Retrieved from https://www.test-king.com/guide-describe-the-purpose-and-functions-of-various-network-devices.htm