IWCE芝加哥举办的关键LTE通信论坛上的小组成员表示，基于3GPP批准的LTE标准的关键任务推送通话服务预计明年将向最终用户提供，但生态系统的几个方面需要改进，这样的服务才能与LMR语音的性能相匹配
. Verizon wireless无线业务产品管理经理Leonardo Gonzalez表示，Verizon计划2019年引入MCPTT服务，他预计这些服务长期内会有很大的发展。
IWCE芝加哥举办的关键LTE通信论坛上的小组成员表示，基于3GPP批准的LTE标准的关键任务推送通话（MCPTT）服务预计明年将向最终用户提供，但生态系统的几个方面需要改进，这样的服务才能与LMR语音的性能相匹配
尽管业界对LTE上的MCPTT何时或是否能够取代LMR系统成为第一响应者关键任务语音通信的主要提供商有着相当大的猜测，但所有专家一致认为，MCPTT将是LMR的补充技术，尤其是短期内
Verizon wireless无线业务产品管理经理Leonardo Gonzalez表示，Verizon计划2019年引入MCPTT服务，他预计这些服务长期内会有很大的发展。一个挑战是，与近距离服务（ProSe）相关的范围（MCPTT标准用于直接模式通信）受到以下事实的阻碍：LTE设备通常比LMR设备具有低得多的传输功率水平，并且使用内部天线，而不是LMR无线电上的外部天线
“关键任务PTT是一种增强技术。冈萨雷斯会议上说：“这不是为了完全取代LMR，也不会，因为我们这方面的具体限制。“有了（LMR）收音机，你就可以数英里内拥有对讲机频道，对吧？但我相信有些用户案例中，散文是有价值的。如果你要去的是一个报道可能有点混乱或类似情况的大楼，你可以利用散文的优势，把这个电话转达给别人，这样还是有价值的
“一个我们不知道覆盖范围的地方，林业局可能不会使用它，这就是为什么我们要谈论可部署设备和所有这些（替代网络）技术。但是，LTE世界中，该技术有一些有效的用户案例，可以尝试提供LMR所具备的弹性。”
摩托罗拉解决方案公司（Motorola Solutions）负责MSI系统和宽带应用的高级经理戴夫·多姆布劳斯基（Dave Dombrowski）表示，摩托罗拉解决方案认为，推送通话（push to talk over cellular，PoC）解决方案是增强覆盖范围的有用补充，但LMR仍然是向第一响应者提供关键任务语音的主要方法
多姆布朗斯基说：“他们说（PoC）很好用，但不是警察或消防员。“现，真正喜欢它的是他们的非第一响应者-管理员，管理层，那些离开覆盖区域的人，他们需要回LMR网络的通信
“但是……对于一个跑进着火的大楼的消防员或者一个拿着枪指着他的警察来说，他们没有使用过顶的（PoC解决方案）或这类应用程序。这才是真正的讨论，你什么时候才能达到这样的水平：他们会抢走那台设备，然后（说他们）把我的生活（放它的线上）呢？““
Dombrowski证实，摩托罗拉解决方案公司已经决定，摩托罗拉解决方案公司去年购买的Kodiak技术将成为该公司MCPTT的平台
三星公共部门销售和解决方案部主管雷格·琼斯（Reg Jones）表示，三星已经部署了公共安全LTE，供韩国冬奥会期间的第一反应人员使用。此外，他还表示，三星已经解决了一个经常被提及的问题，目前大多数LTE芯片组都不支持散文
琼斯说：“我们三星制造的芯片组中有散文功能。”。“它设备中。”
当被问及散文的表现时，琼斯拒绝回答，指出三星迄今尚未公布实验室测试和实地测试的结果
琼斯说，至于设备，三星已经开发出具有关键任务特性的设备，而这些美国还没有引入
他说：“如果你看看我们现有的（LTE消费者）设备，它们外部缺少一些绝对必要的硬件功能。”。“你需要一个大按键通话按钮。它不能是一个脆弱的按钮被隐藏起来，这样它设备上看起来很光滑，这样也许你就不会注意到它了。你需要注意它；它必须是显而易见的。SOS按钮必须是红色的，必须很明显。因此，有些设计组件也必须设备外部进行符合人体工程学的设计
“三星，当我们看到这个设备的时候，我们会看到从芯片层到硅，一直到你用来传达信息的硬件按键——按键通话键，SOS键。如果你看看我们韩国和英国部署的两款设备，你会发现其中一些共同的功能。”
对于高服务质量（包括低服务质量）标准的要求，包括高延迟。鉴于此，大多数小组成员表示，他们相信只有运营商集成解决方案，而不是顶级的按键通话应用程序才能符合MCPTT的所有方面
多姆布朗斯基说：“如果我们想要真正的公共安全级别、LMR级别的按键通话（必须）与运营商整合。”。“从最简单的形式来看，它基本上是一个数据应用程序
“当你进行运营商集成时，你可以获得服务质量、优先级和抢占权，因为软件位于运营商的[LTE网络]核心。”
TCCA技术论坛主席Harald Ludwig不同意，他指出，如果运营商愿意接入其网络的关键方面，MCPTT解决方案可以MVNO场景下提供
“当然，你仍然需要一个网络，你需要一个关键任务网络，”路德维希说。“有不同的选择；既不是运营商集成的，也不是过度的。如果您使用基于标准的接口，您可以打开[其他业务模型]
路德维希说，他担心供应商会对他们的按键通话功能做出毫无根据的声明，因为没有测试解决方案来证明产品是否符合MCPTT标准
“目前，每个人都可以声称拥有符合MCPTT的解决方案。每个人都可以说，‘我有一个基于MCPTT标准的解决方案’，但目前还没有一个好的方法向社区证明这一点。最大的问题是让测试设备制造商对其机器上实现测试脚本感兴趣，以便测试公司能够真正测试MCPTT。”
Ludwig6月于德克萨斯州大学站举行的MCPTT plugtests活动中提到了来自不同供应商的MCPTT解决方案的成功互操作性测试。冈萨雷斯重申，Verizon希望其公共安全通信产品（利用虚拟核心）与FirstNet LTE核心完全互操作，包括相互识别网络中的优先权和优先权
“我们相信互操作性是一个关键的组成部分，”他说。“我们已经多次与FirstNet团队联系，讨论这一点，并确保我们带来了互操作性，我们商业方面已经有了互操作性，您可以拨打AT T号码，发送数据和消息或其他任何东西。”
冈萨雷斯和多姆布朗斯基都表示，他们相信MCPTT将未来几年内发生重大变化。Dombrowski指出，LTE Release 13产品代表了MCPTT的第一个版本，并表示大多数基于软件的技术的第一个版本往往存需要修改的bug
Dombrowski说，他相信MCPTT生态系统设备、软件和LTE网络的所有方面都需要改进，然后第一响应者将考虑将该技术排除LMR之外。然而，他相信MCPTT短期内将第一响应者通信中发挥作用
多姆布朗斯基说：“这（MCPTT）成了你的备用按键通话。“我们认为，短期或长期的LMR推送谈话将是你的生命线。这是您的语音…关键任务推送通话网络。LTE端是你的数据你的大数据支持技术和设备，它作为一个备份推送通话应用程序，如果你离开了LMR或LMR推送通话不可用
“未来，当我们符合人体工程学的要求时，设备（支持用户）将目光投向语音和应用程序的大屏幕/大数据……毫无疑问，我们正关注这一点。但这更多的是一种合作，两者之间的互补关系。”
Mission-critical-push-to-talk (MCPTT) services based on the LTE standard approved by 3GPP are expected to be available to end users next year, but several aspects of the ecosystem need to evolve before such offerings can match the performance of LMR voice, according to panelists at IWCE’s Critical LTE Communications Forum in Chicago.
Although there is considerable industry speculation about when—or if—MCPTT over LTE could replace LMR systems as the primary provider of mission-critical voice communications for first responders, all panelists agreed that MCPTT will be complementary technology to LMR, especially in the short term.
Leonardo Gonzalez, manager of wireless business product management for Verizon Wireless, said that Verizon plans to introduce MCPTT services in 2019 and that he expects them to evolve considerably in the long term. One challenge is that the range associated with proximity services (ProSe)—the MCPTT standard for direct-mode communications—is hampered by the fact that LTE devices typically have much lower transmission power levels than LMR devices and utilize internal antennas, instead of the external antennas on LMR radios.
“Mission-critical PTT is an augmentation technology. It was not intended to fully replace LMR, and it will not, because of the specific constraints that we have in that capability,” Gonzalez said during the session. “With [an LMR] radio, you can have a talkaround channel for miles, right? But I do believe that there are user cases where ProSe has value. If you’re going into a building where coverage might be a little bit spotty or something like that, you can take advantage of ProSe to relay that call to somebody else, so there is still value.
“It might not be used by the forest service in a place where there is no coverage—that we know, which is why we’re talking about deployables and all of these [alternative-networking] technologies. But there are valid user cases for that technology to try to provide that resilience that you’ve got in LMR within the LTE world.”
Dave Dombrowski, Motorola Solutions’ senior manager for MSI systems and broadband applications specialist, said Motorola Solutions believes that push-to-talk-over-cellular (PoC) solutions are useful additions to enhance coverage, but LMR will remain the primary method to deliver mission-critical voice to first responders.
“They’re saying [PoC] works great, but it’s not the cop or the fireman,” Dombrowski said. “Right now, it’s their non-first responders that actually love it—more the admin, the management, those type of people who are leaving the coverage area and they need communications back to the LMR network.
“But … for a fireman running into a burning building or a policeman having a gun pointed at him, they’re not using an over-the-top [PoC solution] or these types of applications. That’s really the discussion—when are you going to get to a level that they’re going to grab that device and [say that they are] putting my life [on the line with it]?”
Dombrowski confirmed that Motorola Solutions has decided that the Kodiak technology that Motorola Solutions purchase last year will be the company’s platform for MCPTT.
Reg Jones, Samsung’s direct of public-sector sales and solutions, said that Samsung has deployed public-safety LTE for first-responder use during the Winter Olympics in South Korea. In addition, he said that Samsung has addressed an oft-cited problem—most LTE chipsets today do not support ProSe.
“We have [ProSe functionality in Samsung-made chipsets],” Jones said. “It is in devices.”
When asked about the performance of ProSe, Jones declined to answer, noting that Samsung has not released the results of lab tests and field trials to date.
As for devices, Samsung has developed devices with key mission-critical characteristics that that not been introduced yet in the United States, Jones said.
“If you look at the [LTE consumer] devices that we have, they are missing some absolutely necessary hardware features on the outside,” he said. “You need a large push-to-talk button. It can’t be a flimsy button that’s hidden, so that it looks sleek on the device, so that maybe you don’t notice it. You need to notice it; it needs to be obvious. The SOS button must be red; it must be obvious. So, there are design components that also have to take place ergonomically on the outside of the device.
“At Samsung, when we look at the device, we look at everything from the chip layer—the silicon—all the way up to the hardware keys that you would use to convey a message—a push-to-talk key, an SOS key. If you look at the two devices that we deployed in South Korea and the United Kingdom, you’ll notice some of these common features.”
The MCPTT standard includes stringent standards, including low latency and the need for high quality-of-service (QoS) levels. Given this, most panelists said that they believe only carrier-integrated solutions—as opposed to over-the-top push-to-talk applications—will be able to comply with all aspects of MCPTT.
“Hands down, if we want true public-safety-grade, LMR-grade push to talk, [it has to be] carrier-integrated,” Dombrowski said. “Over-the-top—in its simplest form, it’s basically a data application.
“When you go carrier-integrated, you get that quality of service, priority and preemption, because the software is in the [LTE network] core of the carrier.”
Harald Ludwig, chairman of the TCCA Technical Forum, disagreed, noting that MCPTT solutions could be provided in an MVNO scenario, if the carrier is willing to enable access to key aspects of its network.
“You still need a network, of course, and you need a mission-critical network,” Ludwig said. “There are different options; it’s not either carrier-integrated or over-the-top. You can open up [other business models], if you use standards-based interfaces.”
Ludwig said he is concerned that vendors will make unfounded claims about their push-to-talk capabilities, because there are no testing solutions to certify whether a product meets the MCPTT standard.
“At the moment, everyone can claim to have an MCPTT-compliant solution. Everyone can say, ‘I have an MCPTT standard-based solution.’ But—at the moment—there’s not really a good way to prove this to the community. The biggest issue is to get test-equipment manufacturers interested in implementing test scripts implemented on their machine, so that test houses can really test MCPTT.”
Ludwig cited successful interoperability testing of MCPTT solutions from different vendors at the MCPTT plugtests event in June at College Station, Texas. Gonzalez reiterated Verizon’s desire to have its public-safety-communications offering that leveraged a virtual core be fully interoperable with the FirstNet LTE core, including reciprocal recognition of prioritized and preemptive traffic across the networks.
“We believe that interoperability is a key component,” he said. “We have approached the FirstNet team several times to talk about that and to make sure that we bring interoperability, which we already have on the commercial side—you can call AT T numbers, send data and messages or anything.”
Both Gonzalez and Dombrowski said they believe that MCPTT will evolve significantly during the next several years. Dombrowski noted that LTE Release 13 products represent the first version of MCPTT and said that the first version of most software-based technologies tend to have bugs that need to be revised.
Dombrowski said that he believes all aspects of the MCPTT ecosystem—devices, software and LTE networks—need to improve before first responders will consider trusting the technology to the exclusion of LMR. However, he does believe that MCPTT will have a role in first-responder communications in the short term.
“This [MCPTT] becomes your backup push to talk,” Dombrowski said. “We look at it as, short term—maybe long term—the LMR push to talk is going to be your lifeline. That’s your voice … network for mission-critical push to talk. The LTE side of it is your data—your big data enabling technology and device—and it acts as a backup push-to-talk application, if you leave the coverage area for LMR or LMR push to talk is not available.
“Down the road, when we get the ergonomic right the device [supporting the user] being eyes-forward for voice and big screen/big data for applications … without a doubt, we’re looking at that. But it’s more of a collaboration, a complementary relationship between the two.” |
