With Apple's most recent MacBook update in the rear-view mirror, now's as good a time as any to think about what could be headed to the next generation of the company's notebook lineup.

Of particular interest is embedded mobile broadband, a notable omission to the Mac laptop range that's now stretched into a waiting game of its own. This is the technology that lets your computer tap into cellular networks and use broadband data while on the go, sans a dopey USB adapter or wireless puck.

While seemingly a luxury feature aimed at business travellers a decade ago, embedded 3G, and now 4G, have become increasingly prevalent in PC laptops aimed at consumers. Apple has also embraced the wireless technology in its iPad, having jumped it from the iPhone to the original iPad on AT&T's GSM network, then later, on Verizon's CDMA network with the iPad 2. So what's the holdup in bringing that same technology to Macs Is Apple waiting for something

To the company's credit, it has provided a product that gives its own laptops wireless 3G service, though it's nowhere as seamless as a built-in modem. Since iOS 3.0, users with iPhones and a carrier data plan that supports tethering, can share their phone's connection with their computer over a USB connection or Bluetooth. In the Verizon version of the iPhone 4, Apple introduced a slightly more elegant feature that would let users turn the phone into a Wi-Fi hotspot, something that was later brought to GSM iPhone users in iOS 4.3.

The easiest explanation to throw in at the moment is that the timing has been off on the network side of the equation: 3G as we know it is on the road to being replaced by 4G, which offers a big speed improvement. Speed becomes especially important on computers versus phones because of the things people tend to do on them, like stream videos' download files and e-mail attachments' and run multiple applications that can slurp up data at a faster clip than smartphone apps.

But the carriers and service providers have not made it so easy to get to that promised land of fast, wireless data. 4G as it's been marketed in the States is not truly 4G by the strict definition. There are different flavors of that "4G," like WiMax, HSPA+, and Long Term Evolution (LTE). Providers have placed bets on the competing parts of the spectrum, creating a situation where there's no easy way to buy hardware that will work with them all--though tech is on the way that can do that.

4G-chip maker Beceem, which was acquired by Broadcom back in October, has a chip in development that does both WiMax and LTE. Apple uses Broadcom's wireless chips in the iPad as well as the iPhone, and for Wi-Fi on its Macs. A similar dual-mode chip initiative was put forth by Sequans at Mobile World Congress last month. Intel, which supplies chips for Apple's notebooks and desktops is also said to be working on a similar solution of its own. In the interim that leaves device makers like Apple, as well as consumers, having to pick a standard and stick to it.

The 4G laptop scene On the PC-side of things, the vast majority of machines with embedded WWAN chipsets have already made the move to WiMax. A quick search on retailer Best Buy's site shows that 47 of its 151 PC laptops for sale have WiMax, with just one opting for the older 3G. According to one broadband-chip expert CNET spoke with, the simplest explanation for that is that Clearwire, which serves up WiMax, beat others to the punch by setting up its network fast and wide, leaving device makers to respond in kind. But that could change going forward.

"We expect LTE to be the most successful 4G standard, but right now it's Clearwire that got out there early," Linley Gwennap, principal analyst at chip consulting firm The Linley Group, said in a phone interview last week.

Gwennap downplayed the importance of built-in WWAN chipsets, saying carriers made both joining and changing platforms an easy affair with USB modems that are cross platform and can be used on multiple machines. This approach has also lent itself to better 4G battery life than what's been seen on some early 4G phones, since laptops had a higher capacity battery.

"Typically the way this works with the laptops is you get a USB stick and you plug it in, so it draws power from the laptop. In that case, the power draw isn't significant," Gwennap said. "What people are complaining about is trying to put 4G into a smartphone, where you draw it down from a cell phone battery. Then the power draw is going to be a problem."

Gwennap did say that like any other piece of technology, embedded broadband chipsets will get cheaper, draw less power, and take up less space inside of computers. However that would be over "the next couple of years."

The long rumor Signs that Apple is mulling a broadband modem in its notebook computers have swirled for years, from pure conjecture to patent filings to company job postings that sought out wireless experts. None have offered a clear picture' several have hinted that it's tantalizingly close.

The patented notebook with the antenna.

Last August, Apple filed for a rather interesting patent of a notebook computer with an antenna that could be installed and removed from the top lid. Similar to the Smart Cover that's available for the iPad 2, or the company's remote control on the side of the iMac, this would simply latch on or break away using magnets, making the accessory a temporary fixture. In a new patent that was filed just last week, the company offered up a slightly different design, building a space for the removable antenna module right into the lid, so the antenna wouldn't stick out, and so there'd presumably be a way to store the antenna when on the go.

Three years ago, following the MacBook Air's introduction, a USA Today interview with Apple CEO Steve Jobs made note that the company had explored putting 3G into the first generation MacBook Air, but eventually decided against it based on how much extra room it took up, and that computer buyers would be restricted to a carrier. Both of those hurdles seem to have been overcome with the iPad 2, given that Apple sells versions for both CDMA and GSM phone networks in a device that's slimmer than the iPhone, and manages to get 9 hours of rated battery life while surfing the Web.

Following the introduction of the first generation MacBook Air, it was widely expected that Apple would then bring the feature to the next iteration of the laptop, though with its release back in October, that proved not to be the case. Interestingly enough, a survey put out by Apple last month, which was nabbed by AppleInsider, suggested that the company still had a model of the Air with WWAN in mind. The survey offered up several wireless data related questions, including a detailed section on situations where participants would use 3G versus Wi-Fi while computing on the go.

Apple has also increased its WWAN footprint, posting, back in 2009, Mac Hardware Group job listings for a quality assurance engineer with expertise in 3G wireless WAN. This was followed months later by the release of Mac OS X 10.6 (dubbed "Snow Leopard"), which dramatically increased the number of supported WWAN products. These were the aforementioned USB modems that have been one of the only ways to get 3G and 4G service piped right into a Mac.

So where does that leave us now If those patents for a neat, removable antenna turn out to bear fruit, such technology is likely to come as part of an all new MacBook design. Since the last big one was in late 2008 with the move to the unibody enclosure, it's likely another major laptop generation will come sooner rather than later. Until then, consumers don't seem to mind too much though. Mac sales continue to grow, and even outpace those in the PC market.

Something that could certainly change things is the recently announced planned acquisition of T-Mobile USA by AT&T, which promises to speed up the deployment of its 4G LTE network to what the company says will be 95 percent of the U.S. population when finished. AT&T has been Apple's business partner since the rollout of the first iPhone, and had been the phone's exclusive carrier in the U.S. up until the device was brought to Verizon earlier this year.

Even so, the AT&T and T-Mobile merger deal still needs to clear regulatory hurdles, and the combining of those networks will likely take even longer. Not to mention the fact that that still doesn't solve the original problem of keeping computer buyers from being stuck with a provider, or the issue of making a product that can work around the globe. Until all that's cleared up, the situation will continue to be a game of wait and see--though that's one Apple has gotten pretty good at.