Technology Comparison: Mx-DMA vs SCPC [A Tale of 3 Return Technologies, PART 2]

Wednesday 4 June 2014
Technology Comparison: Mx-DMA vs SCPC [A Tale of 3 Return Technologies, PART 2]

Article

"A Tale of Return Technologies" is published in 3 parts. This is [Part 2]. You can get an overview and background information by reading published intro article: "A Tale of 3 Return Technologies in 3 Parts".

In the previous episode [Part 1] we demystified the Newtec Mx-DMA™ or Cross-Dimensional Multiple Access return technology, which is implemented on the Newtec Dialog® Platform. In short we can say that Mx-DMA combines the best qualities of SCPC and MF-TDMA return technologies over satellite and solves the difficult choice of having to select either of them. It provides MF-TDMA-like on-demand variable bandwidth allocation with SCPC-like performance efficiency

Obviously the proof of the pudding is in the eating. In this episode we will compare the Mx-DMA return technology performance against SCPC in terms of efficiency gains.


Return Channel comparison: MX-DMA vs SCPC 

 By Koen Willems, Market Director at Newtec

How Much Bandwidth Can Newtec Dialog and Mx-DMA Help you Save?

The true answer to this question lies in your particular network details. Although the savings are, by default, substantial, whether it is more than 40% or more than 20% depends on a number of variables. That’s why we have presented the concrete savings based on very representative examples based on a star topology satellite network of 20 terminals, spread over Sub-Saharan Africa (see Figure 1). The following example mainly focuses on the return channel technologies SCPC and Newtec Mx-DMA.

The table below lists the different satellite network parameters for the use case:

  • Satellite location: -7.5°E
  • Transponder: 36 MHz Ku-band
  • EIRP: 45 dBW
  • G/T: 1 dB/K
  • SCPC terminal: 1.8m antenna, 8W BUC
  • Hub: 4.9m antenna in Geneva
  • Rain model: ITU-R P.618-10
  • System margin: 1 dB
  • Link availability: 99.8%

Figure 1: Example satellite network with Newtec Dialog HUB6501 1IF Hub Module and Newtec MDM3x00 modems
Figure 1: Example satellite network with Newtec Dialog HUB6501 1IF Hub Module and Newtec MDM3x00 modems

Use Case SCPC: Leased Line Services in Ku-band
Step 1: Implementing Fixed Rate Mx-DMA

In the first case the satellite service provider runs leased line services for its customer. In the Service Level Agreement between both companies a dedicated throughput per site at 99.8% availability in Ku-band has been determined. SCPC is traditionally selected as the most optimal technology for leased line types of networks. But how does it perform against the Newtec Mx-DMA technology when we consider the return channels?

When implementing 20 separate return channels using DVB-S2 technology with a 20% roll-off factor and short frames, the total occupied bandwidth for 18 Mbps throughput equals 12.44 MHz. To achieve the dedicated service levels for SCPC DVB-S2 it is required to have terminals based on a 1.8m antenna and 8W BUC design.

For the same 18 Mbps of dedicated throughput over the leased lines, Newtec’s fixed rate Mx-DMA only requires 8.06 MHz satellite bandwidth. In other words, by deploying Newtec Dialog and the Newtec Mx-DMA return technology, 35% savings (see figure 2) can immediately be generated for this leased line network.

Figure 2: Comparison of performance of Fixed Rate Newtec Mx-DMA and SCPC
Figure 2: Comparison of performance of Fixed Rate Newtec Mx-DMA and SCPC

Step 2: Implementing Statistical Multiplexing on Top of Fixed Rate Mx-DMA

We can bring the efficiency gains to an even higher level by engaging the full potential of Newtec’s Mx-DMA technology. In the above sizing exercise, each of the 20 sites get the dedicated return throughput according to its service profile, resulting in the total aggregate capacity of 18 Mbps in the return link.

However, it is very unlikely all 20 sites will simultaneously use the full service profile dedicated capacity. As a consequence satellite service operators can apply a statistical multiplexing gain on the aggregated capacity compared to the sum of the individual links (which is also common practice in terrestrial networks). The statistical multiplexing will not burden the end-user experience or the Service Level Agreements (SLA). Newtec Mx-DMA technology and its on-demand bandwidth allocation fully support the “statistical multiplexing in the sky” feature.

For this leased line network a conservative 25% statistical multiplexing gain has been considered for the 20 sites, reducing the throughput from 18 to 13.5 Mbps.

By implementing statistical multiplexing together with Newtec Mx-DMA technology, satellite service providers can realize a 52% bandwidth saving, (see figure 3) compared to DVB-S2, going from 12.44 MHz to 6.02 MHz satellite bandwidth.

Figure 3: Comparison of performance of Fixed Rate Newtec Mx-DMA with Statistical Multiplexing and SCPC
Figure 3: Comparison of performance of Fixed Rate Newtec Mx-DMA with Statistical Multiplexing and SCPC

Use Case Newtec Mx-DMA versus SCPC Results

This use case clearly demonstrates the Newtec Mx-DMA benefit over SCPC as return technology. For dedicated capacity services Mx-DMA HRC typically brings three equally attractive options when compared to SCPC:

  • Saves more than 35% bandwidth
  • Adds more then 35% more content or increases the quality of the content
  • Serves 54% more customers within the same bandwidth
  • By applying statistical multiplexing together with Mx-DMA the bandwidth gain will be increased to 52%.

On this bombshell we invite you to check out the third and final episode [Part 3] in this blog series on Mx-DMA. In the next episode we will compare Mx-DMA and MF-TDMA return technologies through a similar use case set up.

With this information in the back pocket we are ready to jump to the two use cases where we will compare the return Mx-DMA technology gains against SCPC and MF-TDMA. So tune in for the next episode of this blog post and keep a watchful eye on the Newtec website or social media. And share your comments. 

Here you find an overview of all 3 parts.

Warm regards,

Koen


Koen Willems

Market Director at Newtec

Comment