Reading Connections – Understanding WiFi and Mobile Hubs as Networks

“Any sufficiently advanced technology is indistinguishable from magic.” Arthur C. Clarke, “Hazards of Prophecy: The Failure of Imagination” (1973).


Introduction

I think the most interesting facet of attempting to understand (or rather demonstrating that I understand) WiFi and Broadband mobile networks is the fundamental, nearly-fractal complexity of exploring the “networks” at the core of connectivity.  A close second, then would be the fact that I was able to locate precisely zero sources that managed to synthesize an understanding of networks at multiple levels of complexity (e.g.: network-level, device-level, data-level, global- or regional-level).

Give me a systems engineer, and I’ll be able to keep up in a conversation about network management and maintenance.  Give me a grandmother with her first laptop and a Time Warner account, and I’ll be able to set up her LAN network.  Give me a challenge of putting the two of them in the same room together and facilitating conversation, and I think I’d go insane before we even agreed on terms.

This is the WiFi antenna from my own model of smartphone, the Motorola Moto X (1st Generation). Functionally equivalent to a household mast antenna from two decades ago in terms of antenna gain, and with approximately twenty times the throughput, this device weighs under a quarter of an ounce, and is less than two inches across. (Source: iFixit.com)

My original notes for explaining this concept here were over seven pages long.  As implied in the epigraph above, WiFi may as well be functionally equivalent to magic for the traditional or typical consumer of digital media.  At the very least, the sum of its apparent parts is certainly far beyond the capability of the whole.

In the end, I settled for discussing simply the device-level, local- or immediate-proximity networks that would be most familiar to the lay reader.  It would certainly behoove the reader to be aware of concerns having to do with frequency, channels, and wavelength, electromagnetic and physical interference sources, baud rate, UL certification, communications protocols,  packet security, firewalls, loss differentiation, or encryption.  To do so, however, would merely move us one layer lower in an infinitely-regressing series of networks that would simply require further illumination, bring about further complexity, and require precise, nuanced technical understanding of everything from quantum theory to advanced cryptography.

Even in reduction after reduction, it would – to put it another way – be indistinguishable from magic.


Understanding Broadband as a First-Order Network

The simplest understanding of wireless networks, then, is the first-order network of things communicating with other things through the process of wireless connectivity.  Subnetworks within this network would include, perhaps, workgroups or subnets in Local Area Networks (LANs), Wireless Local Area Networks (WLANs), and Personal Area Networks (PANs).  Devices themselves may be structurally and hierarchically interpreted as networks of parts which similarly communicate and connect in order to receive, interpret, respond to, and disseminate information (data).  Above the (W)LAN or PAN level, there are Wide Area Networks (WAN), or connections of PANs, LANs, and WLANs (up to and including the entirety of the Internet itself.)

Figure 1: Rudimentary diagram of mobile device connecting to Internet data services and other user devices through telecom network. Carrier services are also connected to the PSTN through the Mobile Switching Center.
Figure 1: Rudimentary diagram of mobile device connecting to Internet data services and other user devices through telecom network. Carrier services are also connected to the PSTN through the Mobile Switching Center.

The mobile broadband environment exists primarily to do four things: 1) connect mobile devices with each other (e.g. cellular telecom), 2) connect mobile devices to “landline” telecom exchange networks (PSTN, or Public Switched Telephone Network), 3) connect mobile devices to the Internet or other public networks, and 4) to connect mobile devices to proximal networks and attached devices (e.g. PANs and WLANs).  For instances 1, 2, and 3, see Figure 1 (left).  For instances 3 and 4, see Figure 2 below right.  The primary challenge in communicating these networks to the lay user is threefold – typical users experience difficulty processing the necessary speed, area, and complexity of such networks, which makes it difficult to parse the reality that a simple voice call over a mobile network may include as many as two dozen “handshakes” between network nodes, including servers, centers, stations, extenders, and other devices.

Figure 2: Rudimentary diagram of mobile device serving as a central node in a Wireless Local Area Network (WLAN).
Figure 2: Rudimentary diagram of mobile device serving as a central “hotspot” node in a Wireless Local Area Network (WLAN) while also connecting with additional devices and networks through Bluetooth, NFC/IR, and RF signals.  Present beyond the Data Carrier/ISP is the Internet itself.

Although Local Area and Personal Networks are significantly less complicated in terms of scale, they are not significantly less complex in terms of the variety of technologies and protocols necessary to process and facilitate data transfer and maintain the total network ecology.  The typical mobile “smartphone” device may have upwards of four or five different wireless communications methods and protocols, including Infrared (IR) transmission and Near Field Communication (NFC) to communicate with line-of-sight devices, WiFi to communicate with WLAN networks, Bluetooth Ultra-High-Frequency signals (BT, UHF) to maintain connection to accessories and local devices, and finally Radio Frequency carrier signals (RF) to connect with the mobile network itself.

Rudimentary diagram of devices interacting in a Local Area Network (LAN).
Figure 3: Rudimentary diagram of devices interacting in a Hybrid Wireless Local Area Network (LAN/WLAN).

Due to this complexity, and the general cultural expectation of smartphones to serve as devices that “just work” as functional nodes, it may be best to instead explore the nature of networks as functional collectives through the LAN/WLAN specifically (See Figure 3.)

Most users will view WLANs as, quite simply, the way to get the Internet onto their personal devices (e.g., laptops, smart televisions, smartphones, WiFi-enabled dishwashers, or even home security systems.)  This interpretation of the network is functional for the vast majority of users; however, such users often do not consider the network as a whole ecology, including subnetworks – such as (at just the first-order network level) the RF connection between a laptop and a wireless mouse, the mediated WiFi communication between a smartphone and a wireless printer, or the facilitated handshake between a device and a central modem/router through a device such as a wireless network repeater or range extender.  They are also not likely to think about less overt elements of the network, such as protocols which allow for burst transmission in order to maintain connectivity during periods of interference, channel switching in order to minimize latency, appointment of Internet Protocol addresses (IP) to devices using the Dynamic Host Configuration Protocol (DHCP), et cetera.  And yet, without these functions, the WLAN network is effectively disconnected – not only from the outside world, but from itself.


ACTIVITY – Devices as Nodes, Connections as Edges, Networks as… Networks

In the face of such complexity of protocols, forms, devices, and connections, it may be best to consider WiFi/Mobile devices as nodes within a networked topology, and consider connections as edges of topological map of a digital territory, rather than as a bi-directional relationship between individual devices.

Indeed, though we do not often think of such limitations overtly, spacial proximity and other physical restrictions are often as important to the topology of a network as is any connection protocol.

As an exercise in understanding the complexity, scale, and speed of such networks and your device’s place within a hybrid wireless/wired topology, please consider completing one (or all!) of the following activity steps:

1) Through your command prompt or systems terminal, run a netstat analysis of your device’s connections over WLAN, LAN, and WAN (for Windows CMD prompt, enter “netstat f”; for MacOS terminal, enter “$ netstat ap tcp”.)

After reviewing your active connections within and without your local network, consider the following questions:

  • Sample Netstat analysis - Windows Command Prompt
    Figure 4: Sample Netstat analysis – Windows Command Prompt

    Did you expect this many connections routed through your device at once? More? Fewer?

  • Can you identify specific connections and the processes they are driving (e.g. internet radio, Netflix, cloud storage, software update services, etc.)?
  • What percentage of your connections are internal?  External?

2) Visit http://www.monitis.com/traceroute/  and track your mobile/wireless devices’ IP node connections in “pinging” a WAN network node (e.g., your favorite website).

Figure 4: Sample traceroute - baidu.com from Norfolk, VA.
Figure 5: Sample traceroute – baidu.com from Norfolk, VA.  This search traveled 11,380 kilometers at approximately 51,000,000 m/s – averaging 1/6th the speed of light over transmission.

Using IP Geolocation, the service will trace and locate connections for each of your server hops in connecting to another website.  For instance, it required 223ms for my laptop to connect to the Chinese search engine, Baidu.com, which has its primary server in Beijing.  In order to reach that server, my connection was routed through 24 separate nodes.  For your own search, consider the following questions:

  • Were you surprised to learn where servers were located for your favorite web content?
  • Consider the latency between your device and final connection node.  Approximately how far (and how quickly) have you “traveled” for access to this node?

3) Login to your wireless router for your home network and poke around.

Most routers default to a browser-accessible IP address at 192.168.1.1 or 192.168.0.1 – if not, you can locate your local host IP by entering “ipconfig – all” in your Windows CMD prompt, or “ifconfig” in your MacOS terminal.  Enter your localhost IP to access your router controls.  Consider locating your active connections tab (location will vary according to router manufacturer, model, and firmware) and seeing who and what is connected to your network.

Figure 6: Sample connected devices on WiFi network. Notice that device IDs often indicate device location, type, or owner depending upon settings, type, and configuration.
Figure 6: Sample connected devices on WiFi network. Notice that device IDs often indicate device location, type, or owner depending upon settings, type, and configuration.
  • Can you identify what devices (and how many) are currently (or recently) connected to your network?  What connections stand out?  Does anything you see here surprise you?  (e.g. “Dan’s iPhone” was last connected to my network on Friday, January 15th. However, due to a formatting bug, Dan’s “license” on my network will never expire; rather, it is set to expire in December of 1901, a date which will never occur within the system.)
  • Have you ever worked inside your own network configuration before?  What features surprise you?  What features were you unaware were available in your own network?

 

4) Finally, consider what these activities reveal about the breadth, complexity, and scale of data networks.

We’ve already investigated how many connections must be parsed outside the local network to connect to external resources.  Consider this in coordination with the internal network data from this activity.  Think about the following:

  • How many processes (approximately) must take place in order for your phone, for example, to receive something like a Facebook update push notification over broadband, or for your laptop to receive an email over WiFi?
  • Given the fragmented, multi-faceted sub-networks through which data must travel to reach your device (and vice versa), what sorts of data hierarchy, protocols, and technology must be in place in the physical world to facilitate this communication?  Consider looking into energy or financial costs for maintaining a for-profit data center, for instance.
  • Given the complexity of these networks, consider the following (philosophical) questions:  Where is the Internet? Does your device access it, or does it exist within it?  If the WiFi/Broadband network is broadcasting actively even when you are not connected to it, does the Internet exist in your home even if you are not “attached” to the network?

References

Brain, M., Wilson, T. V., & Johnson, B. (2001). How WiFi Works. Retrieved January 18, 2016, from http://computer.howstuffworks.com/wireless-network1.htm

Coustan, D., Strickland, J., & Perritano, J. (2001). How Smartphones Work. Retrieved January 18, 2016, from http://electronics.howstuffworks.com/smartphone.htm

Marling, C. (n.d.). Mobile Broadband Beginners Guide: What is mobile broadband and how does it work? Retrieved January 18, 2016, from https://www.broadbandgenie.co.uk/mobilebroadband/help/mobile-broadband-beginners-guide

Online Visual Traceroute. (n.d.). Retrieved January 18, 2016, from http://www.monitis.com/traceroute/

Why Use Networks? | IGCSE ICT. (n.d.). Retrieved January 18, 2016, from http://www.igcseict.info/theory/4/why/index.html

 

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