Carrier Aggregation (CA) vs. Bonding

We are often asked, “Isn’t bonding just a fancy term for Carrier Aggregation? Doesn’t everyone do that?”.

While there are some common aspects to both of these technologies, they are also quite different in some other ways. We could spend a lot of time diving into the technical details of both topics, but I’m not going to do that here - I’ll just help break down the important fundamentals:

Carrier Aggregation (CA) - This refers to a single modem/SIM ability to talk to more than one LTE channel on a single network at a time. This is usually 2 or more LTE channels on 2 or more LTE bands. This allows you to connect to the same SIM/Network using more than one slice of spectrum. Carrier Aggregation is a technology specific to LTE networks and modems that support it.

The practical benefits here are

  1. Faster speeds - since you can talk on two channels at once, you get the speed of both channels
  2. Somewhat smoother connectivity - Since your connection dynamically can shift between these frequencies, you will be able to shift between channels/frequencies that have better connectivity as you move around or as the local environment changes. Handoff/addition/subtraction of CA bands is generally seamless (assuming you maintain connectivity to at least one in the process).

What Carrier Aggregation doesn’t do:

  1. CA doesn’t combine two “Carriers” networks - While the term may be confusing to the industry overall, the C in Carrier Aggregation refers to the LTE channel in use, not the carrier’s name like Verizon or AT&T

  2. CA doesn’t extend coverage - Since CA is only giving you access to more channels simultaneously on a single carrier/network, you won’t see any change in the effective coverage area, you’re still limited to the footprint of that single network.

Bonding - This refers to the ability of Peplink’s SpeedFusion, Packet level SD-WAN, to combine the bandwidth of two or more different WANs of any technology. To be able to combine WANs from different providers and technologies, you need a way to intelligently direct packets to each link as line conditions change, and then you need a device to re-assemble and maintain this connectivity as packets shift between the WANs available. Some things to note about bonding:

  1. You must use a service like SpeedFusion Cloud or use another remote endpoint like a FusionHub or a 2nd Peplink router to achieve Bonding - Since TCP/IP rules must be followed, shifting packets between different networks requires this end-end architecture to maintain session consistency.

  2. CA can be used with Bonding - If you are using a router that has multiple CA capable modems, each of those modems and simultaneous frequencies can be bonded together, giving you CA from more than one SIM/network.

  3. Bonding can give you better coverage - Since you can seamlessly shift packets from one LTE network to another LTE network, you can effectively merge the coverage area of two different LTE networks

  4. There are practical limits to how you would use bonding - As an example, you shouldn’t bond LTE and Satellite connections to expect greater throughput. Since the latency of these connections is dramatically different, that won’t be a realistic expectation. However, you can use these two together for seamless handoff between the two, or to use WAN smoothing to ensure mission critical applications are supported by both networks for the ultimate in consistency and resiliency.

Our SpeedFusion Whitepaper can help dive into more details on many of these topics.