PARTNER CONTENT: Dynamic spectrum sharing, or DSS, has become a hot topic lately as a way for mobile operators to migrate their 4G networks to 5G.
Dynamic spectrum sharing (DSS) allows operators to use the same spectrum bands for different radio access technologies. In recent quarters, vendors have positioned it primarily as a way to help operators evolve their 4G networks to support 5G in the face of finite spectrum resources. Though some operators will prefer to dedicate separate frequency bands to 4G and 5G, DSS allows them to share the same spectrum and to adjust the amount of spectrum available to each technology based on user needs that are assessed in real time and rapidly changing. The technology has particular relevance for operators that are deploying 5G in existing low- or mid-band spectrum in order to achieve broad coverage with 5G services while making more efficient use of spectrum assets.
Some operators have pointed out that DSS involves tradeoffs: the network management “overhead” added to the traffic consumes bandwidth and thus could impact the user experience. Still, to other operators, the net value is clear. In the U.S., for example, AT&T and Verizon both have plans to deploy DSS; Verizon plans to enable DSS in its network mid-year and activate it in the back half of the year. Their competitors, meanwhile, Sprint and T-Mobile, whose spectrum assets allow them to rely less on sharing, have publicly downplayed the value of DSS. Outside the U.S. operators have been testing the technology around the globe.
This report provides a snapshot of the different approaches and positions that major radio access network (RAN) vendors took to the subject of DSS in early 2020.
Multiple RAN vendors included DSS among the topics they planned to emphasize at MWC20 before the event was cancelled.
No RAN vendor has done more to promote DSS than Ericsson, which is so committed to signaling its authority in this area that it refers to the concept not as “DSS” but “ESS – Ericsson Spectrum Sharing.” Ericsson has been very proactive on this front, evangelizing the concept throughout 2019 and announcing its general availability on February 27, 2020.
Ericsson has stressed the fact that its DSS is software-upgradable for Ericsson RAN products that have been on the market since 2015. The vendor has also touted as a competitive differentiator its portfolio’s ability to re-allocate spectrum in 1-millisecond increments (however, Huawei claims the same 1-ms level of dynamism, and Samsung says its solution will as well when it launches in H2 2020).
Ericsson has also cited multiple examples of operators that have deployed its DSS — including Swisscom, Telstra, and Ooredoo. These represent a wide global distribution of operators (Europe, Australia, the Middle East), underscoring Ericsson’s early focus on this market. But a key incentive for Ericsson’s proactivity in this area has been major operators such as AT&T and Verizon that have expressed interest in deploying DSS this year in the U.S. – a market where Ericsson’s top competitors, Nokia and Samsung, have been much less vocal about DSS, aiding Ericsson’s efforts to distinguish itself. At the same time, Ericsson’s list of operator references show it gaining traction in markets where it competes with China-based vendors that have also been developing DSS.
Huawei has been aggressive in contesting Ericsson’s claims of DSS leadership. For starters, Huawei has, in two ways, challenged Ericsson’s efforts to portray itself as early to market: Huawei has argued that the CloudAIR solution it’s been offering for many years is a kind of DSS (the distinction being that CloudAIR focused on sharing 2G and 3G traffic with 4G, whereas today’s DSS, as most industry members use the term, refers to 4G/5G sharing). CloudAIR has been deployed at more than 340,000 sites in more than 170 networks, the vendor said.
Huawei says its DSS capability became generally available in Q4 2019, in line with Ericsson’s earlier expectations for its own timing but months ahead of Ericsson’s actual announcement of market availability in February. Also, as previously noted, Huawei has matched Ericsson’s claims of spectrum allocations every 1-ms, challenging another argument for Ericsson’s differentiation in this area.
Huawei has endeavored to hold on to its mind share in this area by describing plans to make available later in 2020 a next-generation version of DSS it calls “Hybrid DSS.” This new offering is defined by three new capabilities:
5G – instead of just two.
In mid-February, ZTE announced its “SuperDSS” solution, which allows DSS among three technologies at once – 2G/4G/5G or 3G/4G/5G. (ZTE also sometimes adds support for Narrowband IoT to that list, but not consistently.) It is essentially an evolution of the Magic Radio solution ZTE has offered for years and applied to 2G, 3G, and 4G – and now extended to 5G. In this way, ZTE’s approach resembles Huawei’s CloudAIR approach to DSS.
ZTE positions this support for legacy technologies as helpful in supporting voice services for operators that have been slow to transition their voice services to next-generation technologies such as LTE. However, ZTE’s decision to brand its solution “SuperDSS” rather than a version of “Magic Radio” or “Magic Radio Pro” (leveraging its existing brands to underscore its experience in this area) communicates the extent to which it views DSS as distinct from legacy spectrum sharing technologies. This may be, more than anything, recognition of the popularity of DSS as an industry buzzword, something Ericsson was key in achieving. But this inconsistency in branding misses an opportunity to reinforce the message of ZTE’s track record in spectrum-sharing.
ZTE’s pledge to make its DSS available in Q2 2020 puts the vendor behind Ericsson and Huawei. And unlike Ericsson, ZTE didn’t include specific operator references in the press release announcing its solution, conceding a slight edge to Ericsson in terms of publicizing real-world proof points. ZTE also specifies its solution’s support of 1800 MHz or 2100 MHz, mid-band spectrum that overlooks, at least initially, the needs some operators will have for DSS in low bands.
Nokia is the only one of the top three RAN vendors not to have made DSS generally available as of this writing. In late February, company executives said DSS was in the final stages of testing and would come to market “imminently.” Meanwhile, as Ericsson was trumpeting DSS, Nokia mildly downplayed its value, pointing out the aforementioned “overhead” issue and its impact on spectral efficiency, and raising the concern that sharing spectrum could shortchange new 5G subscribers by forcing them to share more network capacity with 4G, leaving 5G users disappointed in their service.
For operators that are interested in DSS, Nokia’s lagging posture is especially unwelcome, following so soon after the vendor acknowledged (a) problems with its radio system-on-a-chip strategy, which hampered its 5G RAN operations in 2019 and (b) having invested in commercializing a particular type of Massive MIMO product – those with 18 transceivers and receivers – that failed to find market demand. In the weeks after Nokia’s longtime CEO stepped down in the wake of these matters, the company clearly does not want to be talking about trailing behind in any 5G RAN areas.
Samsung has been relatively quiet on the topic of DSS, consistent with the company’s characteristically conservative posture in public messaging. The company plans to launch a DSS offering sometime in H2 2020, which Samsung says is aligned with the needs of its customers. In terms of competitive differentiation, Samsung says its DSS will support coordination in 10-ms or 1-ms increments and apply to both traditional integrated base stations and those with separate distributed radio units. The vendor also plans to connect DSS to its virtual RAN efforts, supporting DSS in vRAN and traditional networks and even between the two. Because most of Samsung’s major RAN competitors generally don’t embrace vRAN or Open RAN disaggregated base stations, Samsung’s approach here is differentiating, and aids its goals of using unconventional architectures to disrupt the market. However, has not been publicly vocal or transparent on these matters, nor has it been especially early to market, allowing other vendors such as Ericsson to control the public narrative and broadly project superior authority on this topic.
Author: Edward Gubbins