Tablet computers are great media devices but much of their usage is going to require some form of network connectivity. This is vital for functions such as browsing the web, checking email or streaming audio and video. As a result, network connectivity is built into every tablet PC that is available on the market. There are still some major differences between the tablets when it comes to their network features and this guide hopes to clarify some of the choices available to consumers.
Wi-Fi is the most ubiquitous form of wireless networking technology. Pretty much every mobile device now comes with some form of Wi-Fi built into the device. This includes all tablet PCs currently on the market. The technology is designed for local area networking so it alone will not connect you to the internet. Instead, it allows connection into a home wireless network that shares a network broadband connection or a public hotspot with internet access. Since public hotspots are very common in many locations including coffee shops, libraries and airports, it is generally fairly easy to get connected to the internet.
Now Wi-Fi is comprised of multiple standards that are fairly compatible with one another. Most devices are now shipping with 802.11n Wi-Fi which is the fastest and most flexible of the technologies. The downside is that this can use one or both of the wireless spectrums depending upon what hardware is installed on a tablet. All version will support the 2.4GHz wireless spectrum which is fully compatible with the older 802.11b and 802.11g networks. Better implementations will also include the 5GHz spectrum which is also compatible with 802.11a networks for the widest possible coverage. Typically devices that support both spectrums will be listed with 802.11a/g/n while 2.4GHz only devices will be 802.11b/g/n. Another way to describe a device for both is called daul-band or dual antennae.
Speaking of antennas, another technology that can be found in some tablets is called MIMO. What this does is essentially allow a tablet device to use mutiple antennas to essentially provide increased data range by broadcasting over multiple channels in the Wi-Fi standard. In addition to increased bandwidth, this can also improve reliability and range of a tablet on Wi-Fi networks.
Recently some new 5G Wi-Fi networking products have started to be released. These are based on the 802.11ac standards. These products claim to be able to achived up transfer rates of up to 1.3Gbps which is three times the maximum that 802.11n and similar to that of gigabit ethernet. Like the 802.11a standard, it uses the 5GHz frequency but it is dual-band meaning it is also supports 802.11n on the 2.4GHz frequency. While this is available in router products, it has not made it into any tablets to date.
Here is a breakdown of the various Wi-Fi standards along with their features:
- 802.11a - 54Mbps, 5GHz Band, Used Mainly By Corporations
- 802.11b - 11Mbps, 2.4GHz Band, Most Widely Used Wi-Fi
- 802.11g - 54Mbps, 2.4GHz Band, Most Common High-Speed Wi-Fi
- 802.11n - Up To 450Mbps Standard, 2.4 or 5GHz Band, Fastest Wi-Fi Standard
- 802.11ac - Up to 1.3Gbps, 5GHz Band, Still In Draft Stages
For more information about the various Wi-Fi standards, check out the About.com Computer Networking Guide.
3G/4G Wireless (Cellular)
Any tablet that offers 3G or 4G wireless connectivity has extra costs to it. Consumers will have to pay more in the hardware of the device in order to cover the additional transceivers. Typically this adds roughly one hundred dollars to the cost of the tablet. Now that you have the hardware, if you want to use it, you must sign up for a wireless service plan with a carrier that the tablet is compatible with. It is possible to reduce the cost of the hardware through rebate offers when you sign up with a carrier for extended two year contracts. This is known as hardware subsidies. To determine if this is right for you, check out my Subsidized PC FAQ.
Most data plans with wireless carriers are linked to a data cap that limits how much data you can download over that connection in a given month. Mind you, they don't actually cut you off but instead allow you to keep downloading and then charge you overage fees that are quite high. Some unlimited data plans still have caps on them that allowing downloading up to a certain data amount at the full networks speeds but then reduce your network speeds for any data over the cap. This can make comparing data plans very difficult as it isn't easy to track how much data you might use before you have the device. I would suggest reading the iPad Data Plan Comparison from About.com's Guide to iPads for a better explanation.
3G is currently the most widespread of the wireless data networks within the US. This is based upon with a variety of different technologies but it essentially boils down to either being compatible with GSM or CDMA networks. These run over different frequency and signal technologies so they are not cross compatible within a device. GSM networks are managed by AT&T and T-Mobile while CDMA networks are handled by Sprint and Verizon within the US. Speeds are roughly the same at 1 to 2Mbps but reliability may be better with one network over another in a region. As a result, check coverage maps and reports. Typically, a 3G compatible tablet will be locked into one service provider due to exclusivity contracts within the US that allow the hardware to be locked to a specific provider. As a result, figure out which network you want to use before choosing your tablet.
4G is a bit more complex as there are three major technologies right now on the market with good coverage in many urban region but less so outside of them. If you are even considering to use 4G services, make sure to check coverage maps with the various carriers to see if it is in your region before purchasing the hardware and necessary contracts. The three current standards that are in use include HSPA+, LTE and WiMax.
WiMax is the oldest of these standards and works extremely well at fixed locations with speeds of roughly 3 to 6Mbps and peak rates of roughly 10Mbps. Right now, there are no tablets that use this technology on the market but that may change. The technology is based off microwave wireless technology that has been used on a larger scale but has been reduce to small devices. It is offered through Clear and Sprint services.
HSPA+ is sort of a odd step child of 3G technology. Sometimes it was called 3.5G networks but the telecom companies were able to lobby the standards groups to get it labeled as 4G. The technology is similar to that used with HSPA based 3G networks but allows for speeds between 5 and 8Mbps which is a significant improvement over the older 3G speeds. Currently it is offered through AT&T and T-Mobile services.
LTE is the first real wireless networking standard that was built from new technologies to produce true 4G network speeds. Since it is a new technology, it has very limited network coverage right now that is only in major cities right now. AT&T, Verizon, Sprint and T-Mobile are now offering this service but be sure to check coverage maps to make sure there is coverage where you live and use your tablet.
Here is a quick recap of the three primary 4G services in the US:
- HSPA+ - Speeds between 5 and 8Mps. Offered by AT&T and T-Mobile.
- LTE - Speeds between 5 and 14Mbps. Offered by AT&T, Sprint, T-Mobile and Verizon.
- WiMax - Speeds between 3 and 10Mbps. Offered by Clear and Sprint.>/li>
Bluetooth and Tethering
Bluetooth technology is primary a means of connecting wireless peripherals to mobile devices. This includes items such as keyboards or headsets. The technology can also be used as local networking for transferring files between devices. One function that people may consider using though is tethering.
Tethering is a method of linking a mobile device such as a laptop or tablet with a mobile phone to share the wireless broadband connection. This can theoretically be done with any device that has a wireless broadband connection and Bluetooth with another Bluetooth device. So, a 3G/4G capable tablet could share it with a laptop or a 3G/4G mobile phone could share a connection with a tablet PC. The problem is that most wireless carriers have been able to force the hardware and software companies to lock out these features within the US networks. As a result, it really isn't a very functional method for the average user but is possible for those willing to unlock their devices or pay the carriers for the privelage to use such a feature.
If you are interested in using such a function, check with the wireless carrier and the device manufacturer to ensure that it is possible before buying any hardware. Some carriers have begun to offer it but has additional fees involved. Additionally, the feature could always be removed by the carriers at a later date.
Wireless Base Stations / Mobile Hotspots / MiFi
Wireless base stations or mobile hotspots are a new form technology that allows an individual to connect a wireless router to a high speed wireless network such as 3G or 4G networks and allowing other devices that have standard Wi-Fi to share that broadband connection. The first such device was called the MiFi produced by Novatel networks. While these solutions are not as portable as having the wireless broadband built into the tablet itself, they are useful because it allows the connection to be used with a greater number of devices and gives users the flexibility of purchasing less expensive hardware. The MiFi devices will still be locked into a carrier and require a data contract just like having the wireless contact for a tablet specific 3G/4G service.
Interestingly, some of the new tablets with 4G technology built into them have the possibility of being used at a hotspot for other Wi-Fi enabled devices. This is a very attractive feature for those that have a tablet and a laptop that would like to use both over a single data contract.
Near Field Computing
NFC or near field computing is a relatively new short range networking system. The most common use for the technology right now is as a mobile payment system such as Google Wallet that can be found in a couple of cell phones. Theoretically, it could be used for more than just payment but also for syncing to PCs or other tablets. A few tablets are now begining to feature this technology.