HSPA+ No Substiture for LTE

A follow up to this earlier post on LTE and capacity: Every now and then I see a debate of whether it is better to upgrade from HSPA to HSPA+ or to go to LTE. From a capacity point of view I think it's not an "or" decision, it's rather an "and" decision.

I don't see a reason why operators using LTE as a capacity extension in the 2.6 GHz band should not also upgrade to HSPA+ (before, after or at the same time) to make the best out of of the 2.1 GHz spectrum as well and to support as many HSPA users as possible. True, not all mobile devices will be HSPA+ capable for quite some time, but HSPA+ is backwards compatible thus taking everyone forward.

Especially once current equipment is end of life and replaced by multi-technology and multi-band base stations, potentially with new MIMO antennas that can be used simultaneously in the 2.1 and 2.6 GHz band, it seems rather a natural thing to do to me.

As always, thoughts are welcome.

7 thoughts on “HSPA+ No Substiture for LTE”

  1. Some of the vendors push for an ‘and’ while others push for an ‘or’ 🙂 depending on their market share in HSPA or lack thereof. Would be interesting to see what an operator with 10 MHz in the DD (digital dividend) band would do i.e., HSPA+ or LTE.

  2. Well in my opinion most operators have already made that decision. HSPA+ rollouts have started as indicated by the GSM Association “The GSA survey confirms that 25 HSPA+ commercial systems are in commercial service in 19 countries. 24 HSPA+ networks are capable of a peak downlink data speed of 21 Mbps, using 64QAM modulation. One network supports a peak downlink data speed of 28 Mbps, which is made possible with the use of Multiple Input Multiple Output (MIMO) technology. Several more HSPA+ network deployments are on-going.”

    Sure one day LTE networks will also be rolled out, but I don’t think any operator is planning not to upgrade their network from HSPA until LTE is stable, cost-effective and has reached a basic level of maturity.

    Well besides Verizon I guess which are stuck with a CDMA2000 network and can’t wait for LTE.. 🙂

  3. Hi Mark,

    yes, I agree with you. I think going up to “21 MBit/s” (note the quotes) is pretty much a no-brainer as it doesn’t require a new antenna configuration. I wonder though if all NodeB’s can do this out of the box or if new analog and digital boards are required to handle the additional processing power and 64QAM required for this!? But I guess that’s just a question of money as a site visit is probably required in most cases anyway due to backhaul upgrading.

    I like the wording of the GSM Association ” […] 24 HSPA+ networks are capable of a peak downlink data speed of 21 Mbps […]”. Sounds nice and huge but in practice I guess only few base stations have been upgraded so far to this speed. It would be much more interesting how many base stations have been upgraded including backhaul, i.e. how many spots there are today where this is really necessary. But I guess that’s not a number for a press release 🙂

    Kind regards,

  4. Hi,

    yes, an interesting question if LTE or HSPA will be used in the digital dividend band. I guess that depends on many factors, important ones being:

    – When spectrum is auctioned and how mature LTE is at that time vs. HSPA

    – User device availability for each technology. This will also heavily impact if the spectrum is mainly used to cover rual areas for DSL replacement or true mobile use with portable devices.

    At this time, I’d say there is a good chance we’ll see different operators going both ways.


    typepad@sixapart.com wrote:

  5. The way it looks to be going is that wherever an operator deploys in new spectrum (for capacity expansion, mostly), it’ll likely use the newer LTE technology. Why wouldn’t you?

    But, in general, HSPA operators will continue to upgrade to HSPA+ if their currently deployed equipment allows (as Martin writes, not all of it can be upgraded). Antenna configs are obviously a big challenge for 2×2.

    900 MHz refarmnig could be a bit of a battle ground, but probably, there’s not as much of a conflict as is often portrayed, IMO.

  6. HSPA+ is a relatively short term upgrade path… an end of the road of a long sweet ride.

    MIMO-AAS-OFDMA and advancements in topology are where the industry will focus.

    AT&T’s recent about face on deployment of HSPA+ signals a shift in overall thinking.. that has been brewing for some time. I chatted with Kris Rinne in Dallas yesterday where she had reiterated the plans to move to LTE. I congratulated Kris on the decision to deploy multiple carrier LTE using AWS and 700MHz.

    However, no network technology fits all situations. HSPA+ comes at a cost premium and lacks longevity but many operators may find it expedient.

  7. Hi Gabriel,

    Concerning the antennas I wonder if it is practical to use todays polarized antennas for MIMO!? That would make thinks simpler deployment wise, i.e. the antennas stay in place as they are and just some BTS elements are exchanged. I heard that this is possible some time ago, but can’t remember the source and if it’s possible in practice.


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