What was the sequential increase in unit shipments in the second quarter 
 cracks in the armor yet in terms of the tightness that we're seeing. And certainly, as new fab capacity ramps toward the end of next year, I think that that should get us to the point where we can get back to serving the demand.
Raji Gill -- Needham & Company -- Analyst
And if I could just squeeze one more in terms of the IoT you had mentioned broad based growth across wireless but kind of specific focus on some traction on WiFi; any update there in terms of your WiFi efforts? Thank you.
Matt Johnson -- President
Yeah, this is Matt. So on the WiFi piece; it's been over a year since we completed the acquisition of Redpine. We're very happy with the way that's gone. We've integrated the team, we've seen good market response to the technology and now we're integrating that capability into our ongoing roadmap. It came off from a small base, but we're actually seeing the growth of those WiFi products above the average of our other wireless technologies. So we're seeing good uptick in momentum there. And the fundamental thesis or strategic backdrop for why we did this hasn't changed, if anything we've seen in the last year or two, it's accelerated. So we're happy with where it's at. And we see continuing momentum there.
Raji Gill -- Needham & Company -- Analyst
Appreciate it. Thank you.
Operator
The next question comes from Srini Pajjuri from SMBC Nikko Securities. Please go ahead.
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Thank you, good morning guys. And let me echo my congrats as well for Tyson and Matt. A couple of questions. First, John, can we talk about the channel inventory. I think you said, it went up four days. Could you put it into perspective and also are you comfortable where the inventory is? Or do you plan to kind of try to build additional level of inventory as we head into the second half of the year?
Tyson Tuttle -- Chief Executive Officer
Yeah, Srini, I mean the main thing to say about this is our operations team has done a great job executing more supply get into shipments out and ensuring that we have adequate channel inventory. The inventory is falling, but we are pleased that we're able to elevate our unit shipments on a sequential basis in the second quarter. I mean anticipate doing that again in the third quarter. So that is a relatively normal level of inventory. Ideally, yes, we would like to increase it from, but overall, that is a relatively normal level.
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Got it. And then, just a follow-up on gross margins, John. So your longer-term model is for mid-50%. I'm just trying to understand how we get to mid-50% from the current levels obviously you said there was some benefit in the quarter. But as we go through the next few quarters or next couple of years, should we assume that this is going to be a gradual decline or I mean do you even that -- I mean should we even expect a decline or do you think the mix itself will take care of itself? Or are there any other factors that we should be aware of as we model gross margins?
John Hollister -- Chief Financial Officer
Srini it's of course it's a hard thing to predict, but over time as this market grows and evolves, competition is presence in the market and we're allowing for the possibility of some slight declines over time as we scale the business and building our model to comprehend the possibility if that happen. It may not happen, but we're acknowledging that it's possible that it might happen.
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Got it. Thank you.
Operator
The next question comes from Tore Svanberg from Stifel. Please go ahead.
Tore Svanberg -- Stifel Nicolaus -- Analyst
Yes, thank you and congratulations to Matt and Tyson. Tyson, we're going to miss you a lot. And before we let you off the hook, I was hoping you could just talk a little bit more again about the long-term vision in IoT? Obviously you become a semiconductor leader. I know you've invested a lot in software and security. So as we look in the next few years, how is this IoT business is going to evolve for the company
 cracks in the armor yet in terms of the tightness that we're seeing. And certainly, as new fab capacity ramps toward the end of next year, I think that that should get us to the point where we can get back to serving the demand.
Raji Gill -- Needham & Company -- Analyst
And if I could just squeeze one more in terms of the IoT you had mentioned broad based growth across wireless but kind of specific focus on some traction on WiFi; any update there in terms of your WiFi efforts? Thank you.
Matt Johnson -- President
Yeah, this is Matt. So on the WiFi piece; it's been over a year since we completed the acquisition of Redpine. We're very happy with the way that's gone. We've integrated the team, we've seen good market response to the technology and now we're integrating that capability into our ongoing roadmap. It came off from a small base, but we're actually seeing the growth of those WiFi products above the average of our other wireless technologies. So we're seeing good uptick in momentum there. And the fundamental thesis or strategic backdrop for why we did this hasn't changed, if anything we've seen in the last year or two, it's accelerated. So we're happy with where it's at. And we see continuing momentum there.
Raji Gill -- Needham & Company -- Analyst
Appreciate it. Thank you.
Operator
The next question comes from Srini Pajjuri from SMBC Nikko Securities. Please go ahead.
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Thank you, good morning guys. And let me echo my congrats as well for Tyson and Matt. A couple of questions. First, John, can we talk about the channel inventory. I think you said, it went up four days. Could you put it into perspective and also are you comfortable where the inventory is? Or do you plan to kind of try to build additional level of inventory as we head into the second half of the year?
Tyson Tuttle -- Chief Executive Officer
 Yeah, Srini, I mean the main thing to say about this is our operations team has done a great job executing more supply get into shipments out and ensuring that we have adequate channel inventory. The inventory is falling, but we are pleased that we're able to elevate our unit shipments on a sequential basis in the second quarter. I mean anticipate doing that again in the third quarter. So that is a relatively normal level of inventory. Ideally, yes, we would like to increase it from, but overall, that is a relatively normal level.
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Got it. And then, just a follow-up on gross margins, John. So your longer-term model is for mid-50%. I'm just trying to understand how we get to mid-50% from the current levels obviously you said there was some benefit in the quarter. But as we go through the next few quarters or next couple of years, should we assume that this is going to be a gradual decline or I mean do you even that -- I mean should we even expect a decline or do you think the mix itself will take care of itself? Or are there any other factors that we should be aware of as we model gross margins?
John Hollister -- Chief Financial Officer
Srini it's of course it's a hard thing to predict, but over time as this market grows and evolves, competition is presence in the market and we're allowing for the possibility of some slight declines over time as we scale the business and building our model to comprehend the possibility if that happen. It may not happen, but we're acknowledging that it's possible that it might happen.
Srini Pajjuri -- SMBC Nikko Securities -- Analyst
Got it. Thank you.
Operator
The next question comes from Tore Svanberg from Stifel. Please go ahead.
Tore Svanberg -- Stifel Nicolaus -- Analyst
Yes, thank you and congratulations to Matt and Tyson. Tyson, we're going to miss you a lot. And before we let you off the hook, I was hoping you could just talk a little bit more again about the long-term vision in IoT? Obviously you become a semiconductor leader. I know you've invested a lot in software and security. So as we look in the next few years, how is this IoT business is going to evolve for the company