Converting Southern Linc's iDEN network to the new mission critical CriticalLinc LTE network is a big job, but it's proceeding as planned, according to Southern Linc Engineering Manager Alan McIntyre. Final network and service preparations are underway as Southern Linc's engineering team readies the network for customer use later this year.
In terms of physically building the network, most tower sites from the existing iDEN network were converted to LTE technology using new antennas, radios and cabling. But it's not practical to do this at every site, so additional sites have been built.
"By about mid-year, we will have more than 960 sites in production and operating," McIntyre said. "That's quite an accomplishment when you consider that it took approximately 20 years to build the iDEN network of 855 sites.
"We were able to use many of the existing iDEN sites for LTE, so where we could, we've taken advantage of our existing infrastructure," said McIntyre. "That helped speed some sites along. For the new towers needed to build out the LTE network, we have a rather unique process of acquiring sites and having them built by build-to-suit vendors. This process enables us to have the towers where we want them, at the height we want them.
"So even though we're taking advantage of some existing infrastructure, we're really building the CriticalLinc LTE network from the ground up."
When fully operational, the new CriticalLinc network will offer exciting new features. "We'll have the same calling features as with iDEN," McIntyre said, "but additional features, too, like making cellular calls over Wi-Fi, which we couldn't do with iDEN. You'll be able to hand over a call from Wi-Fi to LTE and vice versa."
Nationwide PTT and data service will also be available through Southern Linc's strategic partnerships.
Features that customers have relied on will be continued with the CriticalLinc network, including voicemail, and text and picture messaging, McIntyre explained.
Built on the state-of-the-art Motorola Solutions WAVE 7000 platform, Linc PTT service will provide true mission critical Push To Talk (MCPTT) service. Southern Linc is the first U.S. carrier to offer this public-sector-grade PTT service on a public LTE network.
"We wanted a true mission critical PTT platform, and after spending almost a year evaluating various platforms, we found that the Motorola system was the best for our needs," McIntyre said. The platform allows the CriticalLinc network to meet the international standards for true mission critical PTT service, as established by the 3GPP governing body.
Network monitoring with the CriticalLinc system will also go above and beyond that offered by iDEN technology. "We went out and sourced a couple of different platforms," McIntyre explained. "One allows us to put probes in the network to monitor traffic flows and to make sure everything's working properly from a core infrastructure perspective. That's pretty big."
McIntyre pointed out that the major advantages of the CriticalLinc network are reliability and security. Redundant data centers in both Birmingham and Atlanta, along with highly resilient emergency power sources at tower sites, will assure that the network goes beyond reliable to true mission critical dependability. And that's the whole idea behind the new CriticalLinc network.
The CriticalLinc network will bring with it many improvements over the existing iDEN network. One that is expected to prove exceptionally useful is MCPTT Talk Group Scanning. Made possible by the new Motorola Solutions WAVE 7000 platform, this MCPTT feature delivers an important benefit not previously available without a special device.
MCPTT Talk Group Scanning enables a person to monitor 10 talk groups at a time for call activity and automatically be engaged in a group call when one of those groups becomes active.
"On our iDEN network, a person can listen to just one talk group at a time," explained WAVE 7000 subject matter expert Robert Didier. "With new mission critical PTT, a person can actually scan up to 100 talk groups. To do that, users will create up to 10 lists of 10 talk groups and then select the list they want to monitor, or â€˜scan'.
"So with the CriticalLinc network, instead of having one group to listen to, you can scan up to 10 groups at a time, and you can switch or update your lists of groups to scan whenever you want. It's a really helpful feature."
"At launch, MCPTT users can create scan lists of provisioned talk groups from their phones," said Didier. "In the future, we will offer account owners the capability of controlling scan lists their employees will be able to listen to." MCPTT Group Call is part of the public-sector based WAVE 7000 system being deployed on the CriticalLinc network. This feature is then enhanced with the Talk Group Scanning feature, so it's sure to be an asset for Southern Linc customers' mission critical operations.
For Southern Linc, it's not enough just to build a great new mission critical network. Our new mission critical PTT application is so robust, you'll see four PTT apps on your new Sonim phone.
Linc PTT lets you make one-to-one PTT calls, group PTT calls, broadcast PTT calls and emergency PTT calls, all over a true mission critical network. This is the main PTT application that provides mission critical PTT communications with extremely low latency. Another advantage is AES 256 site-to-site encryption, which provides a very high level of conversation security.
"For most Southern Linc users, this is the app that is likely to remain open most of the time," explained Rodney Johnson, vice president of sales and marketing for Southern Linc.
The Linc Message app allows users to send and receive text messages without leaving the PTT application. Available late in 2018, this service is part of the High Performance (HP) PTT option, which can be added to any plan for an additional monthly fee. The Linc Message app works within Linc's MCPTT platform and allows users to share pictures, video and voice recordings with other HP PTT users or an HP PTT talk group.
"The way you input a PTT text message, the way you read it and the way you respond to it are all very similar to a normal text message on a typical smartphone," Johnson said. "The magic is, the talk group or PTT ID you talk with every day is now your text group."
Slated for availability late in 2018, Linc Map is a PTT option that displays the locations of other PTT users from a particular enterprise (i.e., a company) on a map. PTT users can touch the map screen and establish a PTT call with an individual or a group shown on the map. Linc Map is only available on the XP8 smartphone due to the touch-screen requirements of the app.
Johnson added, "Both of Linc's LTE phones broadcast a location signal all the time, so all PTT users within an enterprise can be visible with Linc Map regardless of which phone they carry. The ability to view and communicate with those shown on the map requires an XP8 smartphone."
Linc Cockpit is used to establish settings and to create groups of MCPTT users to communicate with. "Think of it as your control center," Johnson said. "Cockpit is an app that lets you do two important things.
"The first is to create scan lists of pre-provisioned talk groups. The second is to cancel an emergency alert."
Linc Cockpit also allows users to change their PTT status, choosing "available" or "busy."
These four apps are just part of an outstanding suite of MCPTT features that makes the CriticalLinc network exceptionally valuable.
As Southern Linc moves to the new mission critical CriticalLinc LTE network, many improvements will come with the move. Nationwide PTT and data service is just one of them. But it's a big one.
"Right out of the gate, when we launch the CriticalLinc network, we'll offer nationwide LTE data and Push To Talk service," said Michael Rosenthal, director of legal and external affairs for Southern Linc. "We also expect to offer nationwide cellular (VoLTE) service, but the timeline for that launch looks like it will be later in 2018."
New in LTE, Southern Linc's nationwide partner carriers will be able to use the CriticalLinc network as well. "Whether they'll make our network available for their customers when they are out of their service area is uncertain, but we have offered to make that available, and we're waiting to see if and when they'll take us up on it."
Among the many advantages of nationwide coverage will be significantly faster data speeds than with iDEN, Rosenthal explained."We believe our PTT service, including its nationwide reach, will be significantly more satisfying to our customers than any other product offered by any other carrier. That's what we're striving for," Rosenthal continued.
When Category 5 Hurricane Irma swept just north of Puerto Rico on September 7 of last year, it left widespread damage and more than one million people without power. But that was just the beginning of what nature had in store for the island. Only 13 days later, on September 20, Hurricane Maria made direct landfall, bringing with it wind speeds of 150 mph. That storm destroyed Puerto Rico's power grid, leaving all 3.4 million residents without electricity. In addition, 95 percent of the island's cell networks were down.
Many stepped up to start the rebuilding effort, including Southern Linc's parent, Southern Company. Transporting equipment by barge to aid in the recovery efforts, the company also sent crews from all four of its affiliated power companies – Georgia Power, Alabama Power, Gulf Power and Mississippi Power – to assist in restoring power to the island.
To work effectively and safely, Southern Company's electric utility crews needed communications they could count on. Enter Southern Linc. RAN Team Leader Joe Sires was there and knows the story. Sires first assembled a team that was handpicked for their depth of experience with satellite communication technology and commercial two-way radio. This included three key RAN technicians: William Nash of Savannah, John Long of South Georgia and Eric Capps of Birmingham.
"We all assembled in Birmingham and flew out together with the Southern Company team. Once we had the team, then came the equipment. The initial deployment of trucks and other equipment transported by barge was waiting for them when they arrived, after several weeks in transit. We actually took a Southern Linc COW a cell site on wheels and a satellite on wheels a SOW for backhaul," said Sires. "This equipment was used to provide Southern Linc coverage in Southern Company's restoration-operation main staging area. It also provided communications for team leaders, managers and material handlers so they could communicate back home to the U.S."
After arriving in Puerto Rico, they realized they needed a lot more equipment to do the job effectively. That's when the Southern Company OPCOs quickly mobilized to get the necessary resources and they loaded up a plane with the additional equipment needed.
But that wasn't the only communications assistance Southern Linc provided. "The second role we played," Sires added, "was providing another type of communication that was a little out of our norm establishing a 450 megahertz two-way radio system. This system allowed restoration personnel to talk to one another from 15 to 30 miles away from the staging area. It also provided emergency communications in the event someone was injured or had some other type of emergency."
Southern Linc Puerto Rico RAN Tech team (L to R): Joe Sires, Eric Capps, local school principal, John Long, William Nash.
Most of the Southern Linc team worked in mountainous terrain that presented unique challenges. In one instance, power crews needed communications in a remote area. Sires and his team scouted a mountain ridge without power for a suitable location to install a communications antenna. The location was so remote that it had no structures of any kind to hold an antenna, so the Linc RAN Tech team got resourceful and repurposed a mobile light tower to hold the antenna.
"The light tower provided us with a telescopic mast and had an onboard generator for power, so we made a mobile repeater station out of it. It worked perfectly on top of that mountain ridge, providing critical communication for the crews working in that area."
On other occasions, Sires and his team had to access areas that were under the jurisdiction of local Spanish-speaking officials. Conquering the language barrier between those officials and the Southern Linc crew was challenging, but the projects were successful.
"Working together with our crews, we set up a critical wireless communications system within just five or six days," Sires said. "It was this system that allowed us to communicate with our crews working in dangerous terrain an hour or two away."
In three weeks on the island, Southern Company teams along with Minnesota Power personnel set nearly 300 power poles and restored power to 4,000 customers without incurring a single injury. This is a significant achievement, considering the adverse working conditions and treacherous terrain.
Today, Puerto Rico still faces many challenges in recovering from the storms, but Joe Sires is proud of the part he and his Southern Linc team played in that effort. When he returned home last month, Les Pevey picked up the baton and traveled to Puerto Rico to support power company efforts. At this writing, Joe is back on the island, continuing to provide communications assistance. We thank Joe, Les and the entire Linc RAN Tech team for creatively providing communications for our power companies' restoration work.