diff --git a/DataFormats/SiPixelDigi/interface/PixelDigi.h b/DataFormats/SiPixelDigi/interface/PixelDigi.h
index af41ca0ce24e7..cca8a5ab5433a 100644
--- a/DataFormats/SiPixelDigi/interface/PixelDigi.h
+++ b/DataFormats/SiPixelDigi/interface/PixelDigi.h
@@ -11,89 +11,94 @@
  * Persistent digi for the Pixels.
  */
 
-class PixelDigi {
-public:
-  typedef unsigned int PackedDigiType;
-  typedef unsigned int ChannelType;
+namespace io_v1 {
+  class PixelDigi {
+  public:
+    typedef unsigned int PackedDigiType;
+    typedef unsigned int ChannelType;
 
-  explicit PixelDigi(PackedDigiType packed_value) : theData(packed_value) {}
+    explicit PixelDigi(PackedDigiType packed_value) : theData(packed_value) {}
 
-  PixelDigi(int row, int col, int adc) { init(row, col, adc); }
-  PixelDigi(int row, int col, int adc, int flag) { init(row, col, adc, flag); }
+    PixelDigi(int row, int col, int adc) { init(row, col, adc); }
+    PixelDigi(int row, int col, int adc, int flag) { init(row, col, adc, flag); }
 
-  PixelDigi(int chan, int adc) {
-    std::pair<int, int> rc = channelToPixel(chan);
-    init(rc.first, rc.second, adc);
-  }
+    PixelDigi(int chan, int adc) {
+      std::pair<int, int> rc = channelToPixel(chan);
+      init(rc.first, rc.second, adc);
+    }
 
-  PixelDigi() : theData(0) {}
+    PixelDigi() : theData(0) {}
 
-  void init(int row, int col, int adc, int flag = 0) {
+    void init(int row, int col, int adc, int flag = 0) {
 #ifdef FIXME_DEBUG
-    // This check is for the maximal row or col number that can be packed
-    // in a PixelDigi. The actual number of rows or columns in a detector
-    // may be smaller!
-    // it is done much better in Raw2Digi...
-    if (row < 0 || row > PixelChannelIdentifier::thePacking.max_row || col < 0 ||
-        col > PixelChannelIdentifier::thePacking.max_column) {
-      std::cout << "PixelDigi constructor: row or column out packing range " << row << ' ' << col << std::endl;
-    }
+      // This check is for the maximal row or col number that can be packed
+      // in a PixelDigi. The actual number of rows or columns in a detector
+      // may be smaller!
+      // it is done much better in Raw2Digi...
+      if (row < 0 || row > PixelChannelIdentifier::thePacking.max_row || col < 0 ||
+          col > PixelChannelIdentifier::thePacking.max_column) {
+        std::cout << "PixelDigi constructor: row or column out packing range " << row << ' ' << col << std::endl;
+      }
 #endif
 
-    // Set adc to max_adc in case of overflow
-    adc = (adc > PixelChannelIdentifier::thePacking.max_adc) ? PixelChannelIdentifier::thePacking.max_adc
-                                                             : std::max(adc, 0);
-
-    theData = (row << PixelChannelIdentifier::thePacking.row_shift) |
-              (col << PixelChannelIdentifier::thePacking.column_shift) |
-              (adc << PixelChannelIdentifier::thePacking.adc_shift) |
-              (flag << PixelChannelIdentifier::thePacking.flag_shift);
-  }
+      // Set adc to max_adc in case of overflow
+      adc = (adc > PixelChannelIdentifier::thePacking.max_adc) ? PixelChannelIdentifier::thePacking.max_adc
+                                                               : std::max(adc, 0);
 
-  // Access to digi information
-  int row() const {
-    return (theData >> PixelChannelIdentifier::thePacking.row_shift) & PixelChannelIdentifier::thePacking.row_mask;
-  }
-  int column() const {
-    return (theData >> PixelChannelIdentifier::thePacking.column_shift) &
-           PixelChannelIdentifier::thePacking.column_mask;
-  }
-  int flag() const {
-    return (theData >> PixelChannelIdentifier::thePacking.flag_shift) & PixelChannelIdentifier::thePacking.flag_mask;
-  }
-  unsigned short adc() const {
-    return (theData >> PixelChannelIdentifier::thePacking.adc_shift) & PixelChannelIdentifier::thePacking.adc_mask;
-  }
-  PackedDigiType packedData() const { return theData; }
+      theData = (row << PixelChannelIdentifier::thePacking.row_shift) |
+                (col << PixelChannelIdentifier::thePacking.column_shift) |
+                (adc << PixelChannelIdentifier::thePacking.adc_shift) |
+                (flag << PixelChannelIdentifier::thePacking.flag_shift);
+    }
 
-  static std::pair<int, int> channelToPixel(int ch) {
-    int row = (ch >> PixelChannelIdentifier::thePacking.column_width) & PixelChannelIdentifier::thePacking.row_mask;
-    int col = ch & PixelChannelIdentifier::thePacking.column_mask;
-    return std::pair<int, int>(row, col);
-  }
+    // Access to digi information
+    int row() const {
+      return (theData >> PixelChannelIdentifier::thePacking.row_shift) & PixelChannelIdentifier::thePacking.row_mask;
+    }
+    int column() const {
+      return (theData >> PixelChannelIdentifier::thePacking.column_shift) &
+             PixelChannelIdentifier::thePacking.column_mask;
+    }
+    int flag() const {
+      return (theData >> PixelChannelIdentifier::thePacking.flag_shift) & PixelChannelIdentifier::thePacking.flag_mask;
+    }
+    unsigned short adc() const {
+      return (theData >> PixelChannelIdentifier::thePacking.adc_shift) & PixelChannelIdentifier::thePacking.adc_mask;
+    }
+    PackedDigiType packedData() const { return theData; }
 
-  static int pixelToChannel(int row, int col) { return (row << PixelChannelIdentifier::thePacking.column_width) | col; }
+    static std::pair<int, int> channelToPixel(int ch) {
+      int row = (ch >> PixelChannelIdentifier::thePacking.column_width) & PixelChannelIdentifier::thePacking.row_mask;
+      int col = ch & PixelChannelIdentifier::thePacking.column_mask;
+      return std::pair<int, int>(row, col);
+    }
 
-  int channel() const { return PixelChannelIdentifier::pixelToChannel(row(), column()); }
+    static int pixelToChannel(int row, int col) {
+      return (row << PixelChannelIdentifier::thePacking.column_width) | col;
+    }
 
-private:
-  PackedDigiType theData;
-};
+    int channel() const { return PixelChannelIdentifier::pixelToChannel(row(), column()); }
 
-// Comparison operators
+  private:
+    PackedDigiType theData;
+  };
 
-//inline bool operator<( const PixelDigi& one, const PixelDigi& other) {
-//  return one.channel() < other.channel();
-//}
+  // Comparison operators
 
-inline bool operator<(const PixelDigi& one, const PixelDigi& other) {
-  return (one.packedData() & PixelChannelIdentifier::thePacking.rowcol_mask) <
-         (other.packedData() & PixelChannelIdentifier::thePacking.rowcol_mask);
-}
+  //inline bool operator<( const PixelDigi& one, const PixelDigi& other) {
+  //  return one.channel() < other.channel();
+  //}
 
+  inline bool operator<(const PixelDigi& one, const PixelDigi& other) {
+    return (one.packedData() & PixelChannelIdentifier::thePacking.rowcol_mask) <
+           (other.packedData() & PixelChannelIdentifier::thePacking.rowcol_mask);
+  }
+}  // namespace io_v1
 #include <iostream>
-inline std::ostream& operator<<(std::ostream& o, const PixelDigi& digi) {
-  return o << " " << digi.channel() << " " << digi.adc();
-}
-
+namespace io_v1 {
+  inline std::ostream& operator<<(std::ostream& o, const PixelDigi& digi) {
+    return o << " " << digi.channel() << " " << digi.adc();
+  }
+}  // namespace io_v1
+using PixelDigi = io_v1::PixelDigi;
 #endif
diff --git a/DataFormats/SiPixelDigi/interface/PixelDigiCollection.h b/DataFormats/SiPixelDigi/interface/PixelDigiCollection.h
index 64a8af962fa83..1114fec370e83 100644
--- a/DataFormats/SiPixelDigi/interface/PixelDigiCollection.h
+++ b/DataFormats/SiPixelDigi/interface/PixelDigiCollection.h
@@ -6,23 +6,26 @@
 #include <map>
 #include <utility>
 
-class PixelDigiCollection {
-public:
-  typedef std::vector<PixelDigi>::const_iterator ContainerIterator;
-  typedef std::pair<ContainerIterator, ContainerIterator> Range;
-  typedef std::pair<unsigned int, unsigned int> IndexRange;
-  typedef std::map<unsigned int, IndexRange> Registry;
-  typedef std::map<unsigned int, IndexRange>::const_iterator RegistryIterator;
+namespace io_v1 {
+  class PixelDigiCollection {
+  public:
+    typedef std::vector<PixelDigi>::const_iterator ContainerIterator;
+    typedef std::pair<ContainerIterator, ContainerIterator> Range;
+    typedef std::pair<unsigned int, unsigned int> IndexRange;
+    typedef std::map<unsigned int, IndexRange> Registry;
+    typedef std::map<unsigned int, IndexRange>::const_iterator RegistryIterator;
 
-  PixelDigiCollection() {}
+    PixelDigiCollection() {}
 
-  void put(Range input, unsigned int detID);
-  const Range get(unsigned int detID) const;
-  const std::vector<unsigned int> detIDs() const;
+    void put(Range input, unsigned int detID);
+    const Range get(unsigned int detID) const;
+    const std::vector<unsigned int> detIDs() const;
 
-private:
-  std::vector<PixelDigi> container_;
-  Registry map_;
-};
+  private:
+    std::vector<PixelDigi> container_;
+    Registry map_;
+  };
+}  // namespace io_v1
+using PixelDigiCollection = io_v1::PixelDigiCollection;
 
 #endif  // TRACKINGOBJECTS_PIXELDIGICOLLECTION_H
diff --git a/DataFormats/SiPixelDigi/interface/PixelDigiFwd.h b/DataFormats/SiPixelDigi/interface/PixelDigiFwd.h
index 36896c86c7f9e..2686fde81641b 100644
--- a/DataFormats/SiPixelDigi/interface/PixelDigiFwd.h
+++ b/DataFormats/SiPixelDigi/interface/PixelDigiFwd.h
@@ -1,6 +1,9 @@
 #ifndef DataFormats_SiPixelDigi_PixelDigiFwd_h
 #define DataFormats_SiPixelDigi_PixelDigiFwd_h
 
-class PixelDigi;
+namespace io_v1 {
+  class PixelDigi;
+}
+using PixelDigi = io_v1::PixelDigi;
 
 #endif
diff --git a/DataFormats/SiPixelDigi/src/PixelDigiCollection.cc b/DataFormats/SiPixelDigi/src/PixelDigiCollection.cc
index 7a2b26f180400..87248a3f3c6af 100644
--- a/DataFormats/SiPixelDigi/src/PixelDigiCollection.cc
+++ b/DataFormats/SiPixelDigi/src/PixelDigiCollection.cc
@@ -2,67 +2,69 @@
 #include <iostream>
 #include <algorithm>
 
-void PixelDigiCollection::put(Range input, unsigned int detID) {
-  // put in Digis of detID
+namespace io_v1 {
+  void PixelDigiCollection::put(Range input, unsigned int detID) {
+    // put in Digis of detID
 
-  // store size of vector before put
-  IndexRange inputRange;
+    // store size of vector before put
+    IndexRange inputRange;
 
-  // put in PixelDigis from input
-  bool first = true;
+    // put in PixelDigis from input
+    bool first = true;
 
-  // fill input in temporary vector for sorting
-  std::vector<PixelDigi> temporary;
-  PixelDigiCollection::ContainerIterator sort_begin = input.first;
-  PixelDigiCollection::ContainerIterator sort_end = input.second;
-  for (; sort_begin != sort_end; ++sort_begin) {
-    temporary.push_back(*sort_begin);
-  }
-  std::sort(temporary.begin(), temporary.end());
+    // fill input in temporary vector for sorting
+    std::vector<PixelDigi> temporary;
+    PixelDigiCollection::ContainerIterator sort_begin = input.first;
+    PixelDigiCollection::ContainerIterator sort_end = input.second;
+    for (; sort_begin != sort_end; ++sort_begin) {
+      temporary.push_back(*sort_begin);
+    }
+    std::sort(temporary.begin(), temporary.end());
 
-  // iterators over input
-  PixelDigiCollection::ContainerIterator begin = temporary.begin();
-  PixelDigiCollection::ContainerIterator end = temporary.end();
-  for (; begin != end; ++begin) {
-    container_.push_back(*begin);
-    if (first) {
-      inputRange.first = container_.size() - 1;
-      first = false;
+    // iterators over input
+    PixelDigiCollection::ContainerIterator begin = temporary.begin();
+    PixelDigiCollection::ContainerIterator end = temporary.end();
+    for (; begin != end; ++begin) {
+      container_.push_back(*begin);
+      if (first) {
+        inputRange.first = container_.size() - 1;
+        first = false;
+      }
     }
+    inputRange.second = container_.size() - 1;
+
+    // fill map
+    map_[detID] = inputRange;
   }
-  inputRange.second = container_.size() - 1;
 
-  // fill map
-  map_[detID] = inputRange;
-}
+  const PixelDigiCollection::Range PixelDigiCollection::get(unsigned int detID) const {
+    // get Digis of detID
+
+    auto found = map_.find(detID);
+    PixelDigiCollection::IndexRange returnIndexRange{};
+    if (found != map_.end()) {
+      returnIndexRange = found->second;
+    }
 
-const PixelDigiCollection::Range PixelDigiCollection::get(unsigned int detID) const {
-  // get Digis of detID
+    PixelDigiCollection::Range returnRange;
+    returnRange.first = container_.begin() + returnIndexRange.first;
+    returnRange.second = container_.begin() + returnIndexRange.second + 1;
 
-  auto found = map_.find(detID);
-  PixelDigiCollection::IndexRange returnIndexRange{};
-  if (found != map_.end()) {
-    returnIndexRange = found->second;
+    return returnRange;
   }
 
-  PixelDigiCollection::Range returnRange;
-  returnRange.first = container_.begin() + returnIndexRange.first;
-  returnRange.second = container_.begin() + returnIndexRange.second + 1;
-
-  return returnRange;
-}
+  const std::vector<unsigned int> PixelDigiCollection::detIDs() const {
+    // returns vector of detIDs in map
 
-const std::vector<unsigned int> PixelDigiCollection::detIDs() const {
-  // returns vector of detIDs in map
+    PixelDigiCollection::RegistryIterator begin = map_.begin();
+    PixelDigiCollection::RegistryIterator end = map_.end();
 
-  PixelDigiCollection::RegistryIterator begin = map_.begin();
-  PixelDigiCollection::RegistryIterator end = map_.end();
+    std::vector<unsigned int> output;
 
-  std::vector<unsigned int> output;
+    for (; begin != end; ++begin) {
+      output.push_back(begin->first);
+    }
 
-  for (; begin != end; ++begin) {
-    output.push_back(begin->first);
+    return output;
   }
-
-  return output;
-}
+}  // namespace io_v1
diff --git a/DataFormats/SiPixelDigi/src/classes_def.xml b/DataFormats/SiPixelDigi/src/classes_def.xml
index de7779a5c00ea..210b4cb5ce222 100755
--- a/DataFormats/SiPixelDigi/src/classes_def.xml
+++ b/DataFormats/SiPixelDigi/src/classes_def.xml
@@ -1,28 +1,28 @@
 <lcgdict>
-   <class name="PixelDigi" ClassVersion="10">
-    <version ClassVersion="10" checksum="3516592386"/>
+   <class name="io_v1::PixelDigi" ClassVersion="3">
+    <version ClassVersion="3" checksum="3522132610"/>
    </class>
-   <class name="PixelDigiCollection" ClassVersion="10">
-    <version ClassVersion="10" checksum="544759626"/>
+   <class name="io_v1::PixelDigiCollection" ClassVersion="3">
+    <version ClassVersion="3" checksum="2939008250"/>
    </class>
-   <class name="edm::DetSet<PixelDigi>"/>
-   <class name="std::vector<PixelDigi>"/>
-   <class name="edm::DetSetVector<PixelDigi>"/>
-   <class name="std::vector<edm::DetSet<PixelDigi> >"/>
-   <class name="edm::Wrapper< edm::DetSet<PixelDigi> >" splitLevel="0"/>
-   <class name="edm::Wrapper< std::vector<edm::DetSet<PixelDigi> > >" splitLevel="0"/>
-   <class name="edm::Wrapper< edm::DetSetVector<PixelDigi> >" splitLevel="0"/>
-   <class name="edm::Wrapper<PixelDigiCollection>" splitLevel="0"/>
+   <class name="edm::DetSet<io_v1::PixelDigi>"/>
+   <class name="std::vector<io_v1::PixelDigi>"/>
+   <class name="edm::DetSetVector<io_v1::PixelDigi>"/>
+   <class name="std::vector<edm::DetSet<io_v1::PixelDigi> >"/>
+   <class name="edm::Wrapper< edm::DetSet<io_v1::PixelDigi> >" splitLevel="0"/>
+   <class name="edm::Wrapper< std::vector<edm::DetSet<io_v1::PixelDigi> > >" splitLevel="0"/>
+   <class name="edm::Wrapper< edm::DetSetVector<io_v1::PixelDigi> >" splitLevel="0"/>
+   <class name="edm::Wrapper<io_v1::PixelDigiCollection>" splitLevel="0"/>
 
-   <class name="edmNew::DetSetVector<PixelDigi>"/>
-   <class name="edm::Wrapper< edmNew::DetSetVector<PixelDigi> >"/>
+   <class name="edmNew::DetSetVector<io_v1::PixelDigi>"/>
+   <class name="edm::Wrapper< edmNew::DetSetVector<io_v1::PixelDigi> >"/>
 
-   <class name="SiPixelCalibDigi::datacontainer" ClassVersion="10">
-    <version ClassVersion="10" checksum="3289693280"/>
+   <class name="SiPixelCalibDigi::datacontainer" ClassVersion="3">
+    <version ClassVersion="3" checksum="3289693280"/>
    </class>
    <class name="std::vector<SiPixelCalibDigi::datacontainer>"/>
-   <class name="SiPixelCalibDigi" ClassVersion="10">
-    <version ClassVersion="10" checksum="3382452939"/>
+   <class name="SiPixelCalibDigi" ClassVersion="3">
+    <version ClassVersion="3" checksum="3382452939"/>
    </class>
    <class name="std::vector<SiPixelCalibDigi>"/>
    <class name="edm::DetSet<SiPixelCalibDigi>"/>
@@ -35,8 +35,8 @@
    <class name="edmNew::DetSetVector<SiPixelCalibDigi>"/>
    <class name="edm::Wrapper< edmNew::DetSetVector<SiPixelCalibDigi> >"/>
 
-   <class name="SiPixelCalibDigiError" ClassVersion="10">
-    <version ClassVersion="10" checksum="1495440127"/>
+   <class name="SiPixelCalibDigiError" ClassVersion="3">
+    <version ClassVersion="3" checksum="1495440127"/>
    </class>
    <class name="edm::DetSet<SiPixelCalibDigiError>"/>
    <class name="std::vector<SiPixelCalibDigiError>"/>