A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a cable television (CATV) infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high bandwidth of a cable television network. They are commonly deployed in Australia, Europe, and North and South America. In the USA alone there were 22.5 million cable modem users during the first quarter of 2005, up from 17.4 million in the first quarter of 2004.
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Friday, October 2, 2009
Wednesday, August 26, 2009
Broadband
ADSL modems, a more recent development, are not limited to the telephone's "voiceband" audio frequencies. Some ADSL modems use coded orthogonal frequency division modulation (DMT).
Cable modems use a range of frequencies originally intended to carry RF television channels. Multiple cable modems attached to a single cable can use the same frequency band, using a low-level media access protocol to allow them to work together within the same channel. Typically, 'up' and 'down' signals are kept separate using frequency division multiple access.
New types of broadband modems are beginning to appear, such as doubleway satellite and power line modems.
Broadband modems should still be classed as modems, since they use complex waveforms to carry digital data. They are more advanced devices than traditional dial-up modems as they are capable of modulating/demodulating hundreds of channels simultaneously.
Many broadband modems include the functions of a router (with Ethernet and WiFi ports) and other features such as DHCP, NAT and firewall features.
When broadband technology was introduced, networking and routers were unfamiliar to consumers. However, many people knew what a modem was as most internet access was through dial-up. Due to this familiarity, companies started selling broadband modems using the familiar term "modem" rather than vaguer ones like "adapter" or "transceiver".
Many broadband modems must be configured in bridge mode before they can use a router. For more information visit our friends here.
Cable modems use a range of frequencies originally intended to carry RF television channels. Multiple cable modems attached to a single cable can use the same frequency band, using a low-level media access protocol to allow them to work together within the same channel. Typically, 'up' and 'down' signals are kept separate using frequency division multiple access.
New types of broadband modems are beginning to appear, such as doubleway satellite and power line modems.
Broadband modems should still be classed as modems, since they use complex waveforms to carry digital data. They are more advanced devices than traditional dial-up modems as they are capable of modulating/demodulating hundreds of channels simultaneously.
Many broadband modems include the functions of a router (with Ethernet and WiFi ports) and other features such as DHCP, NAT and firewall features.
When broadband technology was introduced, networking and routers were unfamiliar to consumers. However, many people knew what a modem was as most internet access was through dial-up. Due to this familiarity, companies started selling broadband modems using the familiar term "modem" rather than vaguer ones like "adapter" or "transceiver".
Many broadband modems must be configured in bridge mode before they can use a router. For more information visit our friends here.
Modern Modems and Routers
Modems which use mobile phone lines (GPRS, UMTS, HSPA, EVDO, WiMax, etc.), are known as Cellular Modems. Cellular modems can be embedded inside a laptop or appliance, or they can be external to it. External cellular modems are datacards and cellular routers. The datacard is a PC card or ExpressCard which slides into a PCMCIA/PC card/ExpressCard slot on a computer. The most famous brand of cellular modem datacards is the AirCard made by Sierra Wireless. (Many people just refer to all makes and models as "AirCards", when in fact this is a trademarked brand name.) Nowadays, there are USB cellular modems as well that use a USB port on the laptop instead of a PC card or ExpressCard slot. A cellular router may or may not have an external datacard ("AirCard") that slides into it. Most cellular routers do allow such datacards or USB modems, except for the WAAV, Inc. CM3 mobile broadband cellular router. Cellular Routers may not be modems per se, but they contain modems or allow modems to be slid into them. The difference between a cellular router and a cellular modem is that a cellular router normally allows multiple people to connect to it (since it can "route"), while the modem is made for one connection.
Most of the GSM cellular modems come with an integrated SIM cardholder (i.e, Huawei E220, Sierra 881, etc.) The CDMA (EVDO) versions do not use SIM cards, but use Electronic Serial Number (ESN) instead.
The cost of using a cellular modem varies from country to country. Some carriers implement "flat rate" plans for unlimited data transfers. Some have caps (or maximum limits) on the amount of data that can be transferred per month. Other countries have "per Megabyte" or even "per Kilobyte" plans that charge a fixed rate per Megabyte or Kilobyte of data downloaded; this tends to add up quickly in today's content-filled world, which is why many people are pushing for flat data rates. See : flat rate.
The faster data rates of the newest cellular modem technologies (UMTS, HSPA, EVDO, WiMax) are also considered to be "Broadband Cellular Modems" and compete with other Broadband modems below. For more information visit our friends here.
Most of the GSM cellular modems come with an integrated SIM cardholder (i.e, Huawei E220, Sierra 881, etc.) The CDMA (EVDO) versions do not use SIM cards, but use Electronic Serial Number (ESN) instead.
The cost of using a cellular modem varies from country to country. Some carriers implement "flat rate" plans for unlimited data transfers. Some have caps (or maximum limits) on the amount of data that can be transferred per month. Other countries have "per Megabyte" or even "per Kilobyte" plans that charge a fixed rate per Megabyte or Kilobyte of data downloaded; this tends to add up quickly in today's content-filled world, which is why many people are pushing for flat data rates. See : flat rate.
The faster data rates of the newest cellular modem technologies (UMTS, HSPA, EVDO, WiMax) are also considered to be "Broadband Cellular Modems" and compete with other Broadband modems below. For more information visit our friends here.
Monday, May 18, 2009
Buying Modem Basics
With the advent of broadband access to the internet, you might think that modems have become passe. That's just not the case, as a large majority of users still rely on dial-up service to connect to the internet. However, there are fewer choices in aftermarket modems today simply because virtually all new PCs include an internal modem as standard equipment.
As with all computer and electronics equipment, modems can go bad and may need to be replaced. Modems for use with handheld PCs and PDAs are becoming more widespread. With more Palm and Handspring Visor users wanting access to the internet, e-mail, and other information, these modems are enjoying great popularity.
Modems for desktop PCs come in internal and external models. Most internal models today require a PCI expansion slot. External modems generally require a USB port and operating system support for this feature (Windows 98/Me, Windows 2000/NT, Windows XP, or Mac OS.) Older external models are still available for those who prefer to use a serial port.
All modems these days meet the V.90 standard, which defines operations at 56Kbps. Be aware that this speed is misleading. Because of FCC restrictions on the amount of voltage a modem can put on the line, even a "56K" modem has a speed limit of 53Kbps (with most modems averaging speeds from 40Kbps to 50Kbps). That maximum speed is only in one direction, downloading, and many times, connections are made at a much slower rate. Uploading is performed at 33Kbps at best. A new standard called V.92 has recently been approved, and when implemented by the ISPs (Internet service providers), it will raise the upload speed to as fast as 43Kbps.
Virtually all modems include fax capability. This lets you send and receive faxes using your PC, eliminating the need for a fax machine. Because almost no difference exists in the basic functionality between modems today, manufacturers have started adding special features, such as the ability to send voice messages to other users while communicating online or to automatically differentiate between voice, fax, and data calls.
If you are buying a modem for a laptop, there are two additional features you might want to consider. One is the ability of some laptop PC Card modems to connect to a cellular telephone. Not all modems offer this capability, and even those that do require specific phone models. Another nice feature in PC Card-format modems is built-in jacks that eliminate the need for special connector cables. Wireless modems for laptops or PDAs are also gaining in popularity, although you'll have to stay within a coverage area to maintain your connection.
Broadband internet access methods, such as cable and DSL, require a different type of device. Cable and DSL "modems" do not work the same way as a standard V.90 modem, and most need to be matched to the specific vendor offering the service. You can go into a computer store and purchase a modem for DSL access, but unless it's the one specified by the DSL provider, it might not work.
How to Shop
First, consider whether you want an internal or external modem. External modems require an available port to plug into, but they're easier to install and they offer handy status lights. Internal modems require a free slot inside your PC, and are generally a bit less expensive. Of course, if you use a laptop, you'll want to choose a PC Card modem for maximum portability.
If you're investigating alternative high-speed technologies such as DSL or cable modems, contact your local telephone or cable company before buying equipment. Different localities use different standards, and you'll need to buy equipment that is compatible with your local system.
As with all computer and electronics equipment, modems can go bad and may need to be replaced. Modems for use with handheld PCs and PDAs are becoming more widespread. With more Palm and Handspring Visor users wanting access to the internet, e-mail, and other information, these modems are enjoying great popularity.
Modems for desktop PCs come in internal and external models. Most internal models today require a PCI expansion slot. External modems generally require a USB port and operating system support for this feature (Windows 98/Me, Windows 2000/NT, Windows XP, or Mac OS.) Older external models are still available for those who prefer to use a serial port.
All modems these days meet the V.90 standard, which defines operations at 56Kbps. Be aware that this speed is misleading. Because of FCC restrictions on the amount of voltage a modem can put on the line, even a "56K" modem has a speed limit of 53Kbps (with most modems averaging speeds from 40Kbps to 50Kbps). That maximum speed is only in one direction, downloading, and many times, connections are made at a much slower rate. Uploading is performed at 33Kbps at best. A new standard called V.92 has recently been approved, and when implemented by the ISPs (Internet service providers), it will raise the upload speed to as fast as 43Kbps.
Virtually all modems include fax capability. This lets you send and receive faxes using your PC, eliminating the need for a fax machine. Because almost no difference exists in the basic functionality between modems today, manufacturers have started adding special features, such as the ability to send voice messages to other users while communicating online or to automatically differentiate between voice, fax, and data calls.
If you are buying a modem for a laptop, there are two additional features you might want to consider. One is the ability of some laptop PC Card modems to connect to a cellular telephone. Not all modems offer this capability, and even those that do require specific phone models. Another nice feature in PC Card-format modems is built-in jacks that eliminate the need for special connector cables. Wireless modems for laptops or PDAs are also gaining in popularity, although you'll have to stay within a coverage area to maintain your connection.
Broadband internet access methods, such as cable and DSL, require a different type of device. Cable and DSL "modems" do not work the same way as a standard V.90 modem, and most need to be matched to the specific vendor offering the service. You can go into a computer store and purchase a modem for DSL access, but unless it's the one specified by the DSL provider, it might not work.
How to Shop
First, consider whether you want an internal or external modem. External modems require an available port to plug into, but they're easier to install and they offer handy status lights. Internal modems require a free slot inside your PC, and are generally a bit less expensive. Of course, if you use a laptop, you'll want to choose a PC Card modem for maximum portability.
If you're investigating alternative high-speed technologies such as DSL or cable modems, contact your local telephone or cable company before buying equipment. Different localities use different standards, and you'll need to buy equipment that is compatible with your local system.
Thursday, May 14, 2009
What Kind of Modems Should I Buy?
e have always recommended external modems. In the past, the main reasons for this were that:
* They can be connected to any kind of computer that has a serial port.
* You can monitor the lights and speaker sounds for troubleshooting.
* They don't cause interrupt conflicts or address confusion, as internal modems almost always do.
In recent times, the reasons to stick with external modems are all the more compelling:
* Almost any recent-model modem is bound to have bugs and defects. Therefore it is better to keep it outside your PC, where it can't affect the internal bus, configuration, or interrupt structure of your computer.
* An external modems can be turned off and on to return it to its power-up configuration, as is often necessary when the modem becomes hopelessly confused. Internal modems can be power cycled only by turning your whole computer off and on.
* External modems are almost never "controllerless". To the best of our knowledge, all RPI modems, Winmodems, and other "software assisted" modems are internal PC modems.
* External modems are never "Plug and Play". Plug and Play modems need special OS-specific loaders to be initialized correctly. They can't be used with DOS applications, even in a Windows 95 DOS window. To the best of our knowledge they work only in Windows 95/98, and maybe to some degree also in Linux through the isapnptools software.
We do not recommend or endorse any particular brand of modem. However, we do recommend the following attributes:
* It should be external rather than internal. The extra price is worth it.
* It should follow established ITU-T (formerly CCITT) standards like V.32bis, V.34, V.90, V.42, and V.42bis. If a modem claims to "exceed" standards or "set" standards, beware; it is unlikely to interoperate correctly, or at all, with modems from other manufacturers.
* It must not depend on operating-system-specific drivers or loaders for any of its signal processing, modulation, error-correction, or compression functions. The operating system should be able to make full use of it through its serial-port driver, with the application providing the interface to the modem's command language. Thus you should be able to change or upgrade operating systems without losing the ability to use your modem.
Read the box carefully before buying.
56K modems are designed for only one purpose: to dial up an Internet Service Provider (ISP) that offers 56K service and has a digital connection to the telephone network. If they don't work for other purposes, this is not surprising, since they were not designed for any other purpose.
V.90 is the recently approved ITU-T standard 56K method, whereas X2 and K56flex are competing proprietary methods that preceded the standard. While V.90 is based on the other two, it does not include either one of them, and is only just now appearing on the market.
Basic connection problems can occur if:
* There is more than one analog segment (and therefore more than one analog/digital conversion point) in the telephone circuit between two 56K modems. Of course, you have no control over this. But it is likely if you are calling any host or service that does not have a direct digital link to the phone network. It might also be the case if you are calling out from a PBX, which can involve multiple A/D D/A conversions.
* There is only one analog segment, but it is too long or too noisy.
* Your modem tickles bugs in the other modem, or vice versa.
* Your modem and the other modem (which might or might not be a 56K modem) can not negotiate a common modulation or protocol. It takes more memory than most modems have to accommodate one or two 56K "standards" plus all the others (v.34 and below) and so essential fallback procedures might be lacking.
In theory, the modems should be able to recover from such situations automatically, and agree upon a lower modulation and connection speed. In practice, sometimes the modems become "frozen" or disconnect entirely. The most common complaint is that the modem makes the connection, but there is only a "blue screen" on the other end. That is, the modems are connected, the local modem reports carrier, but no characters are transmitted.
Performance is a totally separate question, and generally hinges upon the specific pair of modems and the connection between them.
* They can be connected to any kind of computer that has a serial port.
* You can monitor the lights and speaker sounds for troubleshooting.
* They don't cause interrupt conflicts or address confusion, as internal modems almost always do.
In recent times, the reasons to stick with external modems are all the more compelling:
* Almost any recent-model modem is bound to have bugs and defects. Therefore it is better to keep it outside your PC, where it can't affect the internal bus, configuration, or interrupt structure of your computer.
* An external modems can be turned off and on to return it to its power-up configuration, as is often necessary when the modem becomes hopelessly confused. Internal modems can be power cycled only by turning your whole computer off and on.
* External modems are almost never "controllerless". To the best of our knowledge, all RPI modems, Winmodems, and other "software assisted" modems are internal PC modems.
* External modems are never "Plug and Play". Plug and Play modems need special OS-specific loaders to be initialized correctly. They can't be used with DOS applications, even in a Windows 95 DOS window. To the best of our knowledge they work only in Windows 95/98, and maybe to some degree also in Linux through the isapnptools software.
We do not recommend or endorse any particular brand of modem. However, we do recommend the following attributes:
* It should be external rather than internal. The extra price is worth it.
* It should follow established ITU-T (formerly CCITT) standards like V.32bis, V.34, V.90, V.42, and V.42bis. If a modem claims to "exceed" standards or "set" standards, beware; it is unlikely to interoperate correctly, or at all, with modems from other manufacturers.
* It must not depend on operating-system-specific drivers or loaders for any of its signal processing, modulation, error-correction, or compression functions. The operating system should be able to make full use of it through its serial-port driver, with the application providing the interface to the modem's command language. Thus you should be able to change or upgrade operating systems without losing the ability to use your modem.
Read the box carefully before buying.
56K modems are designed for only one purpose: to dial up an Internet Service Provider (ISP) that offers 56K service and has a digital connection to the telephone network. If they don't work for other purposes, this is not surprising, since they were not designed for any other purpose.
V.90 is the recently approved ITU-T standard 56K method, whereas X2 and K56flex are competing proprietary methods that preceded the standard. While V.90 is based on the other two, it does not include either one of them, and is only just now appearing on the market.
Basic connection problems can occur if:
* There is more than one analog segment (and therefore more than one analog/digital conversion point) in the telephone circuit between two 56K modems. Of course, you have no control over this. But it is likely if you are calling any host or service that does not have a direct digital link to the phone network. It might also be the case if you are calling out from a PBX, which can involve multiple A/D D/A conversions.
* There is only one analog segment, but it is too long or too noisy.
* Your modem tickles bugs in the other modem, or vice versa.
* Your modem and the other modem (which might or might not be a 56K modem) can not negotiate a common modulation or protocol. It takes more memory than most modems have to accommodate one or two 56K "standards" plus all the others (v.34 and below) and so essential fallback procedures might be lacking.
In theory, the modems should be able to recover from such situations automatically, and agree upon a lower modulation and connection speed. In practice, sometimes the modems become "frozen" or disconnect entirely. The most common complaint is that the modem makes the connection, but there is only a "blue screen" on the other end. That is, the modems are connected, the local modem reports carrier, but no characters are transmitted.
Performance is a totally separate question, and generally hinges upon the specific pair of modems and the connection between them.
Buying Cellular Modems
A cellular modem will let you and your laptop tap into the high-speed wireless 3G networks that blanket the U.S., so you can surf the Web and download files at broadband speeds anywhere you can use your cell phone. Over the past couple of years, modems have become more compact, compatible, and flexible, but you do have to pay for the device itself along with cellular broadband service that'll cost you from $40 to $60 a month. Still, if you want to get online with a fast network that's more ubiquitous than Wi-Fi, here are some tips to keep in mind when picking a carrier and a device.
Understand the Limits
Cellular broadband can't replace good old residential broadband, because every wireless carrier has some sort of a data limit, typically 5GB per month. That's enough for basic Web surfing and e-mail, but not much more. Pop that cap and most service providers will give you a warning; keep going and you'll probably get cut off or charged insanely high overage rates. (If Cricket is your provider, however, it just throttles down your speed for the remainder of the month.) So if you intend to pump a lot of data through your connection, cellular broadband probably isn't for you.
Balancing Price, Speed, and Coverage
AT&T, Sprint, T-Mobile, and Verizon Wireless each charge $60 a month for a cellular modem subscription, while Cricket charges $40 per month and requires no contract. The devices themselves range in price from free up to around $300, depending on what kind of deal you can get when you sign a service contract.
So just how fast is 3G? In our tests, we found that the city you're in matters more than the technology you're using. Depending on various network factors, you can expect download speeds between 800 kilobits per second and 2.5 megabits per second and upload speeds between 300 Kbps and 800 Kbps. 3G doesn't cover the whole nation (it's absent particularly in lower-population areas); if it's not available your connection will drop to 2G, with download speeds of around 100 Kbps for Sprint and Verizon and 120 to 200 Kbps for AT&T and T-Mobile.
AT&T offers 3G coverage in the form of HSDPA 3.6 in portions of 42 states plus Washington, D.C., and Puerto Rico; the carrier is also testing a faster download system, HSDPA 7.2, which should be released in large markets later this year. T-Mobile offers HSDPA 3.6 in portions of 21 states plus Washington D.C.
Sprint, Verizon, and Cricket use EV-DO Rev A. Verizon's 3G coverage is much more solid than the other national carriers', especially in many rural areas and large parts of the northeastern U.S.
Sprint's 3G coverage isn't quite as good as Verizon's. But Sprint is the first carrier to offer 4G (aka WiMAX), the fastest available cell broadband service, with transfer rates of up to 8 Mbps—although it's currently available only in Baltimore and in Portland, Oregon. If you're interested in WiMAX, currently you have one choice: the Sprint 3G/4G USB Modem U300, the only modem that works with both WiMAX and 3G networks (and it works only in Baltimore).
Cricket isn't available nationwide; you'll find it primarily in medium-size and large cities. Cricket uses both EV-DO Rev A and the slower EV-DO Rev 0, which deliver speeds of around 450 to 700 Kbps down and 150 Kbps up. You'll need to check with the carrier as to whether you're in a Rev 0 or a Rev A city, as there's no indication of the difference on Cricket's Web site.
Can't get coverage where you live? WISPs (wireless ISPs) generally use larger, home-based modems, but they're available in many (though not all) small towns where traditional broadband or cellular service can't be found. What's more, they don't carry 5GB limits.
Add a Modem, Embed, or Tether?
If you decide to make the 3G jump, cellular modems aren't the only option. You'll find a wide range of PCs and netbooks with integrated 3G from almost every manufacturer, save for Apple. In our tests, these devices typically deliver solid speed and reception—but of course, you've got to buy a new system, and you may be yoked to one wireless carrier for the life of the PC.
You can also use your existing cell phone as your laptop's modem through a process called "tethering." Not terribly convenient, and often difficult to set up, tethering doesn't require that you buy anything extra or subscribe to a separate service plan, and monthly supplemental charges are typically less than dedicated modem plans. On our tests, tethered phone connections are generally slightly slower than dedicated modem connections.
On Verizon Wireless, the tethering supplement costs $60 per month for feature phones and between $15 and $30 for smartphones, depending on your service plan. (Check out the full list of Verizon tether-ready phones.) With AT&T, smartphones other than the iPhone are generally tetherable, and you'll pay $30 on top of a personal PDA plan. On Sprint, it's $15 on top of many of the $30-or-higher monthly data plans. To find out if your Sprint phone has tethering abilities, select your phone at the carrier's site, and check to see if Sprint SmartView software is available for your model. Cricket doesn't offer tethering, and while it's possible to use your phone as a modem on T-Mobile, it's not officially supported, so you run the risk of getting cut off at any time.
You've Settled on a Modem, Now Choose a Form Factor
There are three varieties of 3G modems: USB devices, PC Cards, and ExpressCards. The latter two are convenient because you put one into a slot on your laptop and leave it there—but, of course, your PC needs to have the right slot. USB modems are more flexible, because every system has at least one USB port, you can plug a modem into one and not have to worry about switching modems when you switch PCs.
When it comes to performance, we haven't found much of a difference between cards and USB modems. In fact, we've found that the same device in the same place can get different speeds at different times. This is usually because of the modem's chipset and built-in antenna configuration—unique factors in every model. We test modems by trying a sequence of uploads and downloads from multiple sites at least seven times, at different times of day, and in different locations. Only when averaged out over multiple tests do trends become clear. The fastest modems available for each carrier typically receive our Editors' Choice.
Once you've decided which type of modem to get, you might want to consider extra features. Some devices come with built-in microSD card readers for accessing the memory card from your phone, or built-in GPS, so you can use your laptop as a portable navigator.
You'll also find models that let you connect an external antenna. If you live, work, or travel in areas where the 3G signal is consistently weaker than about -90 dBm (decibels above 1 milliwatt; there's a signal meter in your connection manager software that will provide this information), you'll get a big boost from an external antenna or amplifier. Unfortunately, antennas are pretty large, and toting one can be cumbersome.
Mac & Linux Compatibility
Make sure your modem is compatible with your PC's operating system. Every modem offered by AT&T, Sprint, T-Mobile, Verizon Wireless, and Cricket works with Windows XP and Vista, and most modems available today work with Mac OS 10.5 (Sprint's 3G/4G USB Modem U300 and T-Mobile's first modem, the webConnect USB Laptop Stick are notable exceptions). The Novatel Ovation U760 for Sprint and Verizon, and the Sierra Wireless 598U and Novatel Merlin EX720 for Sprint are officially Linux-compatible, and unofficial Linux drivers for AT&T's Sierra and Option cards are also available from the manufacturers' Web sites.
Beware: Overseas Surfing Will Cost You
Traveling abroad? Taking your laptop and modem along isn't as easy as it might seem. AT&T modems will work almost everywhere in the world, but if you're leaving the country, you should get a temporary data add-on to your service plan. You can opt for from 20MB to 200MB of data usage ($25 to $229 per month). If you don't have one of these plans, you'll be charged up to $20 per megabyte (that's MB, not GB) for data overseas. Ouch. T-Mobile modems also work abroad, but they don't have add-on plans available—it's just $15 per megabyte outside the U.S. and Canada.
If you're with Verizon, your modem will work in Canada, and the company will sell you a global ExpressCard that works with a $129.99-per-month plan for use in other countries. But you'll need a laptop with an ExpressCard slot. Otherwise, you're stuck with a $20-per-megabyte rate. Sprint will also sell you special international cards and modems but offers no overseas data roaming plan; if you go to Europe, for instance, you'll pay a flat rate of $16 per megabyte.
If you need Internet access outside the U.S., use your hotel Wi-Fi, hunt down hot spots or use a BlackBerry with an international data plan, which is much less expensive than a cellular card plan.
Understand the Limits
Cellular broadband can't replace good old residential broadband, because every wireless carrier has some sort of a data limit, typically 5GB per month. That's enough for basic Web surfing and e-mail, but not much more. Pop that cap and most service providers will give you a warning; keep going and you'll probably get cut off or charged insanely high overage rates. (If Cricket is your provider, however, it just throttles down your speed for the remainder of the month.) So if you intend to pump a lot of data through your connection, cellular broadband probably isn't for you.
Balancing Price, Speed, and Coverage
AT&T, Sprint, T-Mobile, and Verizon Wireless each charge $60 a month for a cellular modem subscription, while Cricket charges $40 per month and requires no contract. The devices themselves range in price from free up to around $300, depending on what kind of deal you can get when you sign a service contract.
So just how fast is 3G? In our tests, we found that the city you're in matters more than the technology you're using. Depending on various network factors, you can expect download speeds between 800 kilobits per second and 2.5 megabits per second and upload speeds between 300 Kbps and 800 Kbps. 3G doesn't cover the whole nation (it's absent particularly in lower-population areas); if it's not available your connection will drop to 2G, with download speeds of around 100 Kbps for Sprint and Verizon and 120 to 200 Kbps for AT&T and T-Mobile.
AT&T offers 3G coverage in the form of HSDPA 3.6 in portions of 42 states plus Washington, D.C., and Puerto Rico; the carrier is also testing a faster download system, HSDPA 7.2, which should be released in large markets later this year. T-Mobile offers HSDPA 3.6 in portions of 21 states plus Washington D.C.
Sprint, Verizon, and Cricket use EV-DO Rev A. Verizon's 3G coverage is much more solid than the other national carriers', especially in many rural areas and large parts of the northeastern U.S.
Sprint's 3G coverage isn't quite as good as Verizon's. But Sprint is the first carrier to offer 4G (aka WiMAX), the fastest available cell broadband service, with transfer rates of up to 8 Mbps—although it's currently available only in Baltimore and in Portland, Oregon. If you're interested in WiMAX, currently you have one choice: the Sprint 3G/4G USB Modem U300, the only modem that works with both WiMAX and 3G networks (and it works only in Baltimore).
Cricket isn't available nationwide; you'll find it primarily in medium-size and large cities. Cricket uses both EV-DO Rev A and the slower EV-DO Rev 0, which deliver speeds of around 450 to 700 Kbps down and 150 Kbps up. You'll need to check with the carrier as to whether you're in a Rev 0 or a Rev A city, as there's no indication of the difference on Cricket's Web site.
Can't get coverage where you live? WISPs (wireless ISPs) generally use larger, home-based modems, but they're available in many (though not all) small towns where traditional broadband or cellular service can't be found. What's more, they don't carry 5GB limits.
Add a Modem, Embed, or Tether?
If you decide to make the 3G jump, cellular modems aren't the only option. You'll find a wide range of PCs and netbooks with integrated 3G from almost every manufacturer, save for Apple. In our tests, these devices typically deliver solid speed and reception—but of course, you've got to buy a new system, and you may be yoked to one wireless carrier for the life of the PC.
You can also use your existing cell phone as your laptop's modem through a process called "tethering." Not terribly convenient, and often difficult to set up, tethering doesn't require that you buy anything extra or subscribe to a separate service plan, and monthly supplemental charges are typically less than dedicated modem plans. On our tests, tethered phone connections are generally slightly slower than dedicated modem connections.
On Verizon Wireless, the tethering supplement costs $60 per month for feature phones and between $15 and $30 for smartphones, depending on your service plan. (Check out the full list of Verizon tether-ready phones.) With AT&T, smartphones other than the iPhone are generally tetherable, and you'll pay $30 on top of a personal PDA plan. On Sprint, it's $15 on top of many of the $30-or-higher monthly data plans. To find out if your Sprint phone has tethering abilities, select your phone at the carrier's site, and check to see if Sprint SmartView software is available for your model. Cricket doesn't offer tethering, and while it's possible to use your phone as a modem on T-Mobile, it's not officially supported, so you run the risk of getting cut off at any time.
You've Settled on a Modem, Now Choose a Form Factor
There are three varieties of 3G modems: USB devices, PC Cards, and ExpressCards. The latter two are convenient because you put one into a slot on your laptop and leave it there—but, of course, your PC needs to have the right slot. USB modems are more flexible, because every system has at least one USB port, you can plug a modem into one and not have to worry about switching modems when you switch PCs.
When it comes to performance, we haven't found much of a difference between cards and USB modems. In fact, we've found that the same device in the same place can get different speeds at different times. This is usually because of the modem's chipset and built-in antenna configuration—unique factors in every model. We test modems by trying a sequence of uploads and downloads from multiple sites at least seven times, at different times of day, and in different locations. Only when averaged out over multiple tests do trends become clear. The fastest modems available for each carrier typically receive our Editors' Choice.
Once you've decided which type of modem to get, you might want to consider extra features. Some devices come with built-in microSD card readers for accessing the memory card from your phone, or built-in GPS, so you can use your laptop as a portable navigator.
You'll also find models that let you connect an external antenna. If you live, work, or travel in areas where the 3G signal is consistently weaker than about -90 dBm (decibels above 1 milliwatt; there's a signal meter in your connection manager software that will provide this information), you'll get a big boost from an external antenna or amplifier. Unfortunately, antennas are pretty large, and toting one can be cumbersome.
Mac & Linux Compatibility
Make sure your modem is compatible with your PC's operating system. Every modem offered by AT&T, Sprint, T-Mobile, Verizon Wireless, and Cricket works with Windows XP and Vista, and most modems available today work with Mac OS 10.5 (Sprint's 3G/4G USB Modem U300 and T-Mobile's first modem, the webConnect USB Laptop Stick are notable exceptions). The Novatel Ovation U760 for Sprint and Verizon, and the Sierra Wireless 598U and Novatel Merlin EX720 for Sprint are officially Linux-compatible, and unofficial Linux drivers for AT&T's Sierra and Option cards are also available from the manufacturers' Web sites.
Beware: Overseas Surfing Will Cost You
Traveling abroad? Taking your laptop and modem along isn't as easy as it might seem. AT&T modems will work almost everywhere in the world, but if you're leaving the country, you should get a temporary data add-on to your service plan. You can opt for from 20MB to 200MB of data usage ($25 to $229 per month). If you don't have one of these plans, you'll be charged up to $20 per megabyte (that's MB, not GB) for data overseas. Ouch. T-Mobile modems also work abroad, but they don't have add-on plans available—it's just $15 per megabyte outside the U.S. and Canada.
If you're with Verizon, your modem will work in Canada, and the company will sell you a global ExpressCard that works with a $129.99-per-month plan for use in other countries. But you'll need a laptop with an ExpressCard slot. Otherwise, you're stuck with a $20-per-megabyte rate. Sprint will also sell you special international cards and modems but offers no overseas data roaming plan; if you go to Europe, for instance, you'll pay a flat rate of $16 per megabyte.
If you need Internet access outside the U.S., use your hotel Wi-Fi, hunt down hot spots or use a BlackBerry with an international data plan, which is much less expensive than a cellular card plan.
Buying the Right 56K Modem
Buying a 56K modem, also known as a dial-up modem or analog modem, can be confusing. There are several different form factors and processor options to choose from.
For example, should you buy a PCI Modem, a USB Modem, or a Serial Modem? What is the difference between USB 1.0 and USB 2.0? Do you need a controller-based modem, a controller-less modem, or a soft modem?
This brief tutorial will explain the different modem options available to help you choose the correct modem for you!
Hardware Modems, DSP-controlled Modems, and Soft Modems 56K modems come with three different processor types:
* Hardware modems, also known as a "controller modems" or "hardware-controlled modems"
* DSP-based modems, also known as a "controller-less modems"
* Software-based modems, also known as "softmodems" or "win modems"
Of these three types, hardware modems are the most powerful. DSP-based modems are the second most powerful, and softmodems are the least powerful.
In order to send and receive data over the Internet or a network, modems have to process outgoing and incoming data streams. Hardware-based modems have special hardware chips onboard that do most of this processing. Because of this, hardware-based modems do not have to rely on sending information to and from the computer’s central processor, which can slow down transmission speeds and place a heavy drain on the computer for performing other tasks.
DSP modems have some of the processing capability of hardware modems, but not all. As a result, they are faster than softmodems but not as fast as hardware modems.
Softmodems must rely almost entirely on the computer’s CPU to process the data. As a result, they are the slowest modems and place the greatest burden on the CPU, which may slow down other applications running on your PC.
How you are going to use the modem generally determines which is the best processor type for you:
* Hardware Modem: If you will use your modem daily for several hours or more you should most likely buy a hardware-based modem.
* DSP Modem: If you plan to use your modem daily for an hour or more then a DSP modem would be the best choice.
* Softmodem: If you plan to use your modem for simple Internet access a few times per week, a softmodem is probably the most suitable.
You should also consider your computer’s processor speed. In general, the slower your computer’s central processor is, the more powerful a modem you should purchase. This is because less powerful modems put more of a strain on the computer’s own processor. So you should only use a weaker modem (softmodem) if you have a fast central processor. You can check your processor’s speed by consulting the documentation for your PC. You can also check within Windows by selecting "Properties" on the "My Computer" icon.
Here are some general guidelines:
* 300 MHz or less: A hardware controlled modem would be best.
* 300 MHz - 1.0 GHz: DSP controlled modem would be best.
* Over 1.0 GHz: Softmodem would be acceptable.
Form Factor: USB Modem, External Serial Modem, PCI Modem, ISA Modem, PCMCIA Modem
56K modems come in 5 different form factors:
1. USB Modem (external)
2. External Serial Modem
3. PCI Modem (internal)
4. ISA Modem (internal)
5. PCMCIA Modem or Laptop Modem (external)
To purchase the correct form factor, you should consider what options are available for your computer, the performance required, and the ease or difficulty of the installation.
1. USB Modem: If you have a USB port available (either USB 1.0, USB 1.1, or USB 2.0) you might consider a USB modem. They are the easiest modems to install, since they do not require you to open your computer case. USB modems can usually be found in DSP and hardware-controlled versions.
2. External Serial Modems: Like USB modems, serial modems are external and easy to install. They are usually hardware controlled and offer excellent performance.
3. PCI Modems: These are the best-selling modems, and are generally the kind of modem that comes installed a new machine. PCI modems come as either DSP modems or softmodems. You should only purchase a PCI modem if you are comfortable opening your PC case and installing a new PCI card.
4. ISA Modems: These are also internal modems. To use an ISA modem, your PC must have an available ISA slot. These slots or usually only found on older PCs. Consult your system documentation to verify your slot type. These are usually hardware controlled modems, sometimes DSP-based.
5. PCMCIA Modems or Laptop Modems: This is a "card"-type modem that can be used only with a laptop. If you have both a laptop and a desktop PC, you might want to purchase a USB modem instead, since it can be used with either type. For simplicity and ease in traveling, a PCMCIA modem is the best choice.
Modem Vendors: Diamond Multimedia, Best Data Products, U.S. Robotics
Some of the leading vendors for 56K modems are Diamond Multimedia, Best Data Products, and U.S. Robotics.
* Diamond Multimedia’s SupraMax modems have been a leading brand of modems for more than a decade.
* Best Data Products has been offering high quality 56K modems for over 20 years. Their SmartOne modems are known for their value and durability.
For example, should you buy a PCI Modem, a USB Modem, or a Serial Modem? What is the difference between USB 1.0 and USB 2.0? Do you need a controller-based modem, a controller-less modem, or a soft modem?
This brief tutorial will explain the different modem options available to help you choose the correct modem for you!
Hardware Modems, DSP-controlled Modems, and Soft Modems 56K modems come with three different processor types:
* Hardware modems, also known as a "controller modems" or "hardware-controlled modems"
* DSP-based modems, also known as a "controller-less modems"
* Software-based modems, also known as "softmodems" or "win modems"
Of these three types, hardware modems are the most powerful. DSP-based modems are the second most powerful, and softmodems are the least powerful.
In order to send and receive data over the Internet or a network, modems have to process outgoing and incoming data streams. Hardware-based modems have special hardware chips onboard that do most of this processing. Because of this, hardware-based modems do not have to rely on sending information to and from the computer’s central processor, which can slow down transmission speeds and place a heavy drain on the computer for performing other tasks.
DSP modems have some of the processing capability of hardware modems, but not all. As a result, they are faster than softmodems but not as fast as hardware modems.
Softmodems must rely almost entirely on the computer’s CPU to process the data. As a result, they are the slowest modems and place the greatest burden on the CPU, which may slow down other applications running on your PC.
How you are going to use the modem generally determines which is the best processor type for you:
* Hardware Modem: If you will use your modem daily for several hours or more you should most likely buy a hardware-based modem.
* DSP Modem: If you plan to use your modem daily for an hour or more then a DSP modem would be the best choice.
* Softmodem: If you plan to use your modem for simple Internet access a few times per week, a softmodem is probably the most suitable.
You should also consider your computer’s processor speed. In general, the slower your computer’s central processor is, the more powerful a modem you should purchase. This is because less powerful modems put more of a strain on the computer’s own processor. So you should only use a weaker modem (softmodem) if you have a fast central processor. You can check your processor’s speed by consulting the documentation for your PC. You can also check within Windows by selecting "Properties" on the "My Computer" icon.
Here are some general guidelines:
* 300 MHz or less: A hardware controlled modem would be best.
* 300 MHz - 1.0 GHz: DSP controlled modem would be best.
* Over 1.0 GHz: Softmodem would be acceptable.
Form Factor: USB Modem, External Serial Modem, PCI Modem, ISA Modem, PCMCIA Modem
56K modems come in 5 different form factors:
1. USB Modem (external)
2. External Serial Modem
3. PCI Modem (internal)
4. ISA Modem (internal)
5. PCMCIA Modem or Laptop Modem (external)
To purchase the correct form factor, you should consider what options are available for your computer, the performance required, and the ease or difficulty of the installation.
1. USB Modem: If you have a USB port available (either USB 1.0, USB 1.1, or USB 2.0) you might consider a USB modem. They are the easiest modems to install, since they do not require you to open your computer case. USB modems can usually be found in DSP and hardware-controlled versions.
2. External Serial Modems: Like USB modems, serial modems are external and easy to install. They are usually hardware controlled and offer excellent performance.
3. PCI Modems: These are the best-selling modems, and are generally the kind of modem that comes installed a new machine. PCI modems come as either DSP modems or softmodems. You should only purchase a PCI modem if you are comfortable opening your PC case and installing a new PCI card.
4. ISA Modems: These are also internal modems. To use an ISA modem, your PC must have an available ISA slot. These slots or usually only found on older PCs. Consult your system documentation to verify your slot type. These are usually hardware controlled modems, sometimes DSP-based.
5. PCMCIA Modems or Laptop Modems: This is a "card"-type modem that can be used only with a laptop. If you have both a laptop and a desktop PC, you might want to purchase a USB modem instead, since it can be used with either type. For simplicity and ease in traveling, a PCMCIA modem is the best choice.
Modem Vendors: Diamond Multimedia, Best Data Products, U.S. Robotics
Some of the leading vendors for 56K modems are Diamond Multimedia, Best Data Products, and U.S. Robotics.
* Diamond Multimedia’s SupraMax modems have been a leading brand of modems for more than a decade.
* Best Data Products has been offering high quality 56K modems for over 20 years. Their SmartOne modems are known for their value and durability.
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